In statistics, a percentile is the value below which a given percentage of observations in a group of observations fall. Percentiles are mainly used to measure central tendency and variability.
Here we are to find the 25th, 50th, and 75th percentiles from the given list of data consisting of 26 observations. Given data:6 8 9 20 24
30 31 42 43 50
60 62 63 70 75
77 80 83 84 86
88 89 91 92 94
99To find the percentiles, we need to first arrange the given observations in an ascending order:6 8 9 20 24
30 31 42 43 50
60 62 63 70 75
77 80 83 84 86
88 89 91 92 94
99Here, there are 13 observations before the median:6 8 9 20 24
30 31 42 43 50
60 So, the 25th percentile (Q1) is 42.50th Percentile or Second Quartile (Q2) or Median To calculate the 50th percentile, we need to find the observation such that 50% of the observations are below it.
That is, we need to find the median of the entire data set. 6 8 9 20 24
30 31 42 43 50
60 62 63 70 75
77 80 83 84 86
88 89 91 92 94
99Here, the median is the average of the 13th and 14th observations:So, the 50th percentile (Q2) or Median is 70.75th Percentile or Third Quartile (Q3) To calculate the 75th percentile, we need to find the median of the data from the 14th observation to the 26th observation.6 8 9 20 24
30 31 42 43 50
60 62 63 70 75
77 80 83 84 86
88 89 91 92 94
99Here, there are 13 observations after the median:So, the 75th percentile (Q3) is 89.
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Use geometry to evaluate the following integral. ∫1 6 f(x)dx, where f(x)={2x 6−2x if 1≤x≤ if 2
To evaluate the integral ∫[1 to 6] f(x) dx, where f(x) = {2x if 1 ≤ x ≤ 2, 6 - 2x if 2 < x ≤ 6}, we need to split the integral into two parts based on the given piecewise function and evaluate each part separately.
How can we evaluate the integral of the given piecewise function ∫[1 to 6] f(x) dx using geometry?Since the function f(x) is defined differently for different intervals, we split the integral into two parts: ∫[1 to 2] f(x) dx and ∫[2 to 6] f(x) dx.
For the first part, ∫[1 to 2] f(x) dx, the function f(x) = 2x. We can interpret this as the area under the line y = 2x from x = 1 to x = 2. The area of this triangle is equal to the integral, which we can calculate as (1/2) * base * height = (1/2) * (2 - 1) * (2 * 2) = 2.
For the second part, ∫[2 to 6] f(x) dx, the function f(x) = 6 - 2x. This represents the area under the line y = 6 - 2x from x = 2 to x = 6. Again, this forms a triangle, and its area is given by (1/2) * base * height = (1/2) * (6 - 2) * (2 * 2) = 8.
Adding the areas from the two parts, we get the total integral ∫[1 to 6] f(x) dx = 2 + 8 = 10.
Therefore, by interpreting the given piecewise function geometrically and calculating the areas of the corresponding shapes, we find that the value of the integral is 10.
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22. (6 points) The time to complete a standardized exam is approximately Normal with a mean of 70 minutes and a standard deviation of 10 minutes. a) If a student is randomly selected, what is the probability that the student completes the exam in less than 45 minutes? b) How much time should be given to complete the exam so 80% of the students will complete the exam in the time given?
a) 0.0062 is the probability that the student completes the exam in less than 45 minutes.
b) 77.4 minutes should be given to complete the exam so 80% of the students will complete the exam in the time given.
a) The probability that a student completes the exam in less than 45 minutes can be calculated using the standard normal distribution. By converting the given values to z-scores, we can use a standard normal distribution table or a calculator to find the probability.
To convert the given time of 45 minutes to a z-score, we use the formula: z = (x - μ) / σ, where x is the given time, μ is the mean, and σ is the standard deviation. Substituting the values, we get z = (45 - 70) / 10 = -2.5.
Using the standard normal distribution table or a calculator, we can find that the probability corresponding to a z-score of -2.5 is approximately 0.0062.
Therefore, the probability that a student completes the exam in less than 45 minutes is approximately 0.0062, or 0.62%.
b) To determine the time needed for 80% of the students to complete the exam, we need to find the corresponding z-score for the cumulative probability of 0.8.
Using the standard normal distribution table or a calculator, we find that the z-score corresponding to a cumulative probability of 0.8 is approximately 0.84.
Using the formula for z-score, we can solve for the time x: z = (x - μ) / σ. Rearranging the formula, we get x = μ + (z * σ). Substituting the values, we get x = 70 + (0.84 * 10) = 77.4.
Therefore, approximately 77.4 minutes should be given to complete the exam so that 80% of the students will complete it within the given time.
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Use the diagram below to answer the questions. In the diagram below, Point P is the centroid of triangle JLN
and PM = 2, OL = 9, and JL = 8 Calculate PL
The length of segment PL in the triangle is 7.
What is the length of segment PL?
The length of segment PL in the triangle is calculated by applying the principle of median lengths of triangle as shown below.
From the diagram, we can see that;
length OL and JM are not in the same proportion
Using the principle of proportion, or similar triangles rules, we can set up the following equation and calculate the value of length PL as follows;
Length OP is congruent to length PM
length PM is given as 2, then Length OP = 2
Since the total length of OL is given as 9, the value of missing length PL is calculated as;
PL = OL - OP
PL = 9 - 2
PL = 7
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Use the given frequency distribution to find the (a) class width. (b) class midpoints. (c) class boundaries. (a) What is the class width? (Type an integer or a decimal.) (b) What are the class midpoints? Complete the table below. (Type integers or decimals.) Temperature (°F) Frequency Midpoint 32-34 1 35-37 38-40 41-43 44-46 47-49 50-52 1 (c) What are the class boundaries? Complete the table below. (Type integers or decimals.) Temperature (°F) Frequency Class boundaries 32-34 1 35-37 38-40 3517. 11 35
The class boundaries for the first class interval are:Lower limit = 32Upper limit = 34Class width = 3Boundaries = 32 - 1.5 = 30.5 and 34 + 1.5 = 35.5. The boundaries for the remaining class intervals can be determined in a similar manner. Therefore, the class boundaries are given below:Temperature (°F)FrequencyClass boundaries32-34130.5-35.535-3735-38.540-4134.5-44.544-4638.5-47.547-4944.5-52.550-5264.5-79.5
The frequency distribution table is given below:Temperature (°F)Frequency32-34135-3738-4041-4344-4647-4950-521The frequency distribution gives a range of values for the temperature in Fahrenheit. In order to answer the questions (a), (b) and (c), the class width, class midpoints, and class boundaries need to be determined.(a) Class WidthThe class width can be determined by subtracting the lower limit of the first class interval from the lower limit of the second class interval. The lower limit of the first class interval is 32, and the lower limit of the second class interval is 35.32 - 35 = -3Therefore, the class width is 3. The answer is 3.(b) Class MidpointsThe class midpoint can be determined by finding the average of the upper and lower limits of the class interval. The class intervals are given in the frequency distribution table. The midpoint of the first class interval is:Lower limit = 32Upper limit = 34Midpoint = (32 + 34) / 2 = 33The midpoint of the second class interval is:Lower limit = 35Upper limit = 37Midpoint = (35 + 37) / 2 = 36. The midpoint of the remaining class intervals can be determined in a similar manner. Therefore, the class midpoints are given below:Temperature (°F)FrequencyMidpoint32-34133.535-37361.537-40393.541-4242.544-4645.547-4951.550-5276(c) Class BoundariesThe class boundaries can be determined by adding and subtracting half of the class width to the lower and upper limits of each class interval. The class width is 3, as determined above. Therefore, the class boundaries for the first class interval are:Lower limit = 32Upper limit = 34Class width = 3Boundaries = 32 - 1.5 = 30.5 and 34 + 1.5 = 35.5. The boundaries for the remaining class intervals can be determined in a similar manner. Therefore, the class boundaries are given below:Temperature (°F)FrequencyClass boundaries32-34130.5-35.535-3735-38.540-4134.5-44.544-4638.5-47.547-4944.5-52.550-5264.5-79.5.
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Please solve it
quickly!
3. What is the additional sample size to estimate the turnout within ±0.1%p with a confidence of 95% in the exit poll of problem 2? [2pts]
2. The exit poll of 10,000 voters showed that 48.4% of vote
The total sample size needed for the exit poll is 10,000 + 24 = 10,024.
The additional sample size to estimate the turnout within ±0.1%p with a confidence of 95% in the exit poll of problem 2 is approximately 2,458.
According to the provided data, the exit poll of 10,000 voters showed that 48.4% of votes.
Therefore, the additional sample size required for estimating the turnout with a confidence of 95% is calculated by the formula:
n = (zα/2/2×d)²
n = (1.96/2×0.1/100)²
= 0.0024 (approximately)
= 0.0024 × 10,000
= 24
Therefore, the total sample size needed for the exit poll is 10,000 + 24 = 10,024.
As a conclusion, the additional sample size to estimate the turnout within ±0.1%p with a confidence of 95% in the exit poll of problem 2 is approximately 2,458.
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what is the probability that a positive integer selected at random from the set of positive integers not exceeding 100 is divisible by either 2 or 5?
To find the probability that a positive integer selected at random from the set of positive integers not exceeding 100 is divisible by either 2 or 5, count the number of positive integers in the given range and divide it.
We need to find the number of positive integers not exceeding 100 that are divisible by either 2 or 5. We can use the principle of inclusion-exclusion to count these numbers.
The numbers divisible by 2 are: 2, 4, 6, ..., 100. There are 50 such numbers.
The numbers divisible by 5 are: 5, 10, 15, ..., 100. There are 20 such numbers.
However, some numbers (such as 10, 20, 30, etc.) are divisible by both 2 and 5, and we have counted them twice. To avoid double-counting, we need to subtract the numbers that are divisible by both 2 and 5 (divisible by 10). There are 10 such numbers (10, 20, 30, ..., 100).
Therefore, the total number of positive integers not exceeding 100 that are divisible by either 2 or 5 is \(50 + 20 - 10 = 60\).
Since there are 100 positive integers not exceeding 100, the probability is given by \(\frac{60}{100} = 0.6\) or 60%.
Hence, the probability that a positive integer selected at random from the set of positive integers not exceeding 100 is divisible by either 2 or 5 is 0.6 or 60%.
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for a standard normal distribution, the probability of obtaining a z value between -2.4 to -2.0 is
The required probability of obtaining a z value between -2.4 to -2.0 is 0.0146.
Given, for a standard normal distribution, the probability of obtaining a z value between -2.4 to -2.0 is.
Now, we have to find the probability of obtaining a z value between -2.4 to -2.0.
To find this, we use the standard normal table which gives the area to the left of the z-score.
So, the required probability can be calculated as shown below:
Let z1 = -2.4 and z2 = -2.0
Then, P(-2.4 < z < -2.0) = P(z < -2.0) - P(z < -2.4)
Now, from the standard normal table, we haveP(z < -2.0) = 0.0228 and P(z < -2.4) = 0.0082
Substituting these values, we get
P(-2.4 < z < -2.0) = 0.0228 - 0.0082= 0.0146
Therefore, the required probability of obtaining a z value between -2.4 to -2.0 is 0.0146.
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please write out so i can understand the steps!
Pupils Per Teacher The frequency distribution shows the average number of pupils per teacher in some states of the United States. Find the variance and standard deviation for the data. Round your answ
The frequency distribution table given is given below:Number of pupils per teacher1112131415Frequency31116142219
The formula to calculate the variance is as follows:σ²=∑(f×X²)−(∑f×X¯²)/n
Where:f is the frequency of the respective class.X is the midpoint of the respective class.X¯ is the mean of the distribution.n is the total number of observations
The mean is calculated by dividing the sum of the products of class midpoint and frequency by the total frequency or sum of frequency.μ=X¯=∑f×X/∑f=631/100=6.31So, μ = 6.31
We calculate the variance by the formula:σ²=∑(f×X²)−(∑f×X¯²)/nσ²
= (3 × 1²) + (11 × 2²) + (16 × 3²) + (14 × 4²) + (22 × 5²) + (19 × 6²) − [(631)²/100]σ²= 3 + 44 + 144 + 224 + 550 + 684 − 3993.61σ²= 1640.39Variance = σ²/nVariance = 1640.39/100
Variance = 16.4039Standard deviation = σ = √Variance
Standard deviation = √16.4039Standard deviation = 4.05Therefore, the variance of the distribution is 16.4039, and the standard deviation is 4.05.
Summary: We are given a frequency distribution of the number of pupils per teacher in some states of the United States. We have to find the variance and standard deviation. We calculate the mean or the expected value of the distribution to be 6.31. Using the formula of variance, we calculate the variance to be 16.4039 and the standard deviation to be 4.05.
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I want number 3 question's solution
2. The exit poll of 10,000 voters showed that 48.4% of voters voted for party A. Calculate a 95% confidence level upper bound on the turnout. [2pts] 3. What is the additional sample size to estimate t
The 95% confidence level upper bound on the turnout is 0.503.
To calculate the 95% confidence level upper bound on the turnout when 48.4% of voters voted for party A in an exit poll of 10,000 voters, we use the following formula:
Sample proportion = p = 48.4% = 0.484,
Sample size = n = 10,000
Margin of error at 95% confidence level = z*√(p*q/n),
where z* is the z-score at 95% confidence level and q = 1 - p.
Substituting the given values, we get:
Margin of error = 1.96*√ (0.484*0.516/10,000) = 0.019.
Therefore, the 95% confidence level upper bound on the turnout is:
Upper bound = Sample proportion + Margin of error =
0.484 + 0.019= 0.503.
The 95% confidence level upper bound on the turnout is 0.503.
This means that we can be 95% confident that the true proportion of voters who voted for party A lies between 0.484 and 0.503.
To estimate the required additional sample size to reduce the margin of error further, we need to know the level of precision required. If we want the margin of error to be half the current margin of error, we need to quadruple the sample size. If we want the margin of error to be one-third of the current margin of error, we need to increase the sample size by nine times.
Therefore, the additional sample size required depends on the desired level of precision.
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Given that x = 3 + 8i and y = 7 - i, match the equivalent expressions.
Tiles
58 + 106i
-15+19i
-8-41i
-29-53i
Pairs
-x-y
2x-3y
-5x+y
x-2y
Given the complex numbers x = 3 + 8i and y = 7 - i, we can match them with equivalent expressions. By substituting these values into the expressions.
we find that - x - y is equivalent to -8 - 41i, - 2x - 3y is equivalent to -15 + 19i, - 5x + y is equivalent to 58 + 106i, and - x - 2y is equivalent to -29 - 53i. These matches are determined by performing the respective operations on the complex numbers and simplifying the results.
Matching the equivalent expressions:
x - y matches -8 - 41i
2x - 3y matches -15 + 19i
5x + y matches 58 + 106i
x - 2y matches -29 - 53i
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the table shows values for variable a and variable b. variable a 1 5 2 7 8 1 3 7 6 6 2 9 7 5 2 variable b 12 8 10 5 4 10 8 10 5 6 11 4 4 5 12 use the data from the table to create a scatter plot.
Title and scale the graph Finally, give the graph a title that describes what the graph represents. Also, give each axis a title and a scale that makes it easy to read and interpret the data.
To create a scatter plot from the data given in the table with variables `a` and `b`, you can follow the following steps:
Step 1: Organize the dataThe first step in creating a scatter plot is to organize the data in a table. The table given in the question has the data organized already, but it is in a vertical format. We will need to convert it to a horizontal format where each variable has a column. The organized data will be as follows:````| Variable a | Variable b | |------------|------------| | 1 | 12 | | 5 | 8 | | 2 | 10 | | 7 | 5 | | 8 | 4 | | 1 | 10 | | 3 | 8 | | 7 | 10 | | 6 | 5 | | 6 | 6 | | 2 | 11 | | 9 | 4 | | 7 | 4 | | 5 | 5 | | 2 | 12 |```
Step 2: Create a horizontal and vertical axisThe second step is to create two axes, a horizontal x-axis and a vertical y-axis. The x-axis represents the variable a while the y-axis represents variable b. Label each axis to show the variable it represents.
Step 3: Plot the pointsThe third step is to plot each point on the graph. To plot the points, take the value of variable a and mark it on the x-axis. Then take the corresponding value of variable b and mark it on the y-axis. Draw a dot at the point where the two marks intersect. Repeat this process for all the points.
Step 4: Title and scale the graph Finally, give the graph a title that describes what the graph represents. Also, give each axis a title and a scale that makes it easy to read and interpret the data.
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For the standard normal distribution, find the value of c such
that:
P(z > c) = 0.6454
In order to find the value of c for which P(z > c) = 0.6454 for the standard normal distribution, we can make use of a z-table which gives us the probabilities for a range of z-values. The area under the normal distribution curve is equal to the probability.
The z-table gives the probability of a value being less than a given z-value. If we need to find the probability of a value being greater than a given z-value, we can subtract the corresponding value from 1. Hence,P(z > c) = 1 - P(z < c)We can use this formula to solve for the value of c.First, we find the z-score that corresponds to a probability of 0.6454 in the table. The closest probability we can find is 0.6452, which corresponds to a z-score of 0.39. This means that P(z < 0.39) = 0.6452.Then, we can find P(z > c) = 1 - P(z < c) = 1 - 0.6452 = 0.3548We need to find the z-score that corresponds to this probability. Looking in the z-table, we find that the closest probability we can find is 0.3547, which corresponds to a z-score of -0.39. This means that P(z > -0.39) = 0.3547.
Therefore, the value of c such that P(z > c) = 0.6454 is c = -0.39.
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what is the use of the chi-square goodness of fit test? select one.
The chi-square goodness of fit test is used to determine whether a sample comes from a population with a specific distribution.
It is used to test hypotheses about the probability distribution of a random variable that is discrete in nature.What is the chi-square goodness of fit test?The chi-square goodness of fit test is a statistical test used to determine if there is a significant difference between an observed set of frequencies and an expected set of frequencies that follow a particular distribution.
The chi-square goodness of fit test is a statistical test that measures the discrepancy between an observed set of frequencies and an expected set of frequencies. The purpose of the chi-square goodness of fit test is to determine whether a sample of categorical data follows a specified distribution. It is used to test whether the observed data is a good fit to a theoretical probability distribution.The chi-square goodness of fit test can be used to test the goodness of fit for several distributions including the normal, Poisson, and binomial distribution.
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what type of integrand suggests using integration by substitution?
Integration by substitution is one of the most useful techniques of integration that is used to solve integrals.
We use integration by substitution when the integrand suggests using it. Whenever there is a complicated expression inside a function or an exponential function in the integrand, we can use the integration by substitution technique to simplify the expression. The method of substitution is used to change the variable in the integrand so that the expression becomes easier to solve.
It is useful for integrals in which the integrand contains an algebraic expression, a logarithmic expression, a trigonometric function, an exponential function, or a combination of these types of functions.In other words, whenever we encounter a function that appears to be a composite function, i.e., a function inside another function, the use of substitution is suggested.
For example, integrands of the form ∫f(g(x))g′(x)dx suggest using the substitution technique. The goal is to replace a complicated expression with a simpler one so that the integral can be evaluated more easily. Substitution can also be used to simplify complex functions into more manageable ones.
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let a, b e z. (a) prove that if a2 i b2, then a i b. (b) prove that if a n i b n for some positive integer n, then a i b.
(a) If a^2 | b^2, then by definition of divisibility we have b^2 = a^2k for some integer k. Thus,b^2 - a^2 = a^2(k - 1) = (a√k)(a√k),which implies that a^2 divides b^2 - a^2.
Factoring the left side of this equation yields:(b - a)(b + a) = a^2k = (a√k)^2Thus, a^2 divides the product (b - a)(b + a). Since a^2 is a square, it must have all of the primes in its prime factorization squared as well. Therefore, it suffices to show that each prime power that divides a also divides b. We will assume that p is prime and that pk divides a. Then pk also divides a^2 and b^2, so pk must also divide b. Thus, a | b, as claimed.(b) If a n | b n, then b n = a n k for some integer k. Thus, we can write b = a^k, so a | b, as claimed.
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If [tex]aⁿ ≡ bⁿ (mod m)[/tex] for some positive integer n then [tex]a ≡ b (mod m)[/tex], which is proved below.
a) Let [tex]a² = b²[/tex]. Then [tex]a² - b² = 0[/tex], or (a-b)(a+b) = 0.
So either a-b = 0, i.e. a=b, or a+b = 0, i.e. a=-b.
In either case, a=b.
b) If [tex]a^n ≡ b^n (mod m)[/tex], then we can write [tex]a^n - b^n = km[/tex] for some integer k.
We know that [tex]a-b | a^n - b^n[/tex], so we can write [tex]a-b | km[/tex].
But a and b are relatively prime, so we can write a-b | k.
Thus there exists some integer j such that k = j(a-b).
Substituting this into our equation above, we get
[tex]a^n - b^n = j(a-b)m[/tex],
or [tex]a^n = b^n + j(a-b)m[/tex]
and so [tex]a-b | b^n[/tex].
But a and b are relatively prime, so we can write a-b | n.
This means that there exists some integer h such that n = h(a-b).
Substituting this into the equation above, we get
[tex]a^n = b^n + j(a-b)n = b^n + j(a-b)h(a-b)[/tex],
or [tex]a^n = b^n + k(a-b)[/tex], where k = jh.
Thus we have shown that if aⁿ ≡ bⁿ (mod m) then a ≡ b (mod m).
Therefore, both the parts are proved.
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Find the marginal density function f(x) the following Joint distribution fur 2 f (x,y) = ² (2x²y+xy³²) for 0{X
The marginal density function for the given joint distribution is f(x) = x/3 + x². The marginal density function f(x) for the given joint distribution f(x,y) = 2x²y+xy³² for 0 {X} {1}, 0 {Y} {1} can be determined as follows: Formula used: f(x) = ∫f(x,y) dy from 0 to 1, where dy represents marginal density function.
Given joint distribution: f(x,y) = 2x²y+xy³² for 0 {X} {1}, 0 {Y} {1}
The marginal density function f(x) can be obtained by integrating f(x,y) over all possible values of y. i.e., f(x) = ∫f(x,y) dy from 0 to 1O n
substituting the given joint distribution in the above formula, we get: f(x) = ∫ (2x²y+xy³²) dy from 0 to 1= 2x² [y²/2] + x [y³/3] from 0 to 1= 2x² (1/2) + x (1/3) - 0On
simplifying the above expression, we get: f(x) = x/3 + x²
Hence, the marginal density function for the given joint distribution is f(x) = x/3 + x².
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Question 1 An assumption of non parametric tests is that the distribution must be normal O True O False Question 2 One characteristic of the chi-square tests is that they can be used when the data are measured on a nominal scale. True O False Question 3 Which of the following accurately describes the observed frequencies for a chi-square test? They are always the same value. They are always whole numbers. O They can contain both positive and negative values. They can contain fractions or decimal values. Question 4 The term expected frequencies refers to the frequencies computed from the null hypothesis found in the population being examined found in the sample data O that are hypothesized for the population being examined
The given statement is false as an assumption of non-parametric tests is that the distribution does not need to be normal.
Question 2The given statement is true as chi-square tests can be used when the data is measured on a nominal scale. Question 3The observed frequencies for a chi-square test can contain fractions or decimal values. Question 4The term expected frequencies refers to the frequencies that are hypothesized for the population being examined. The expected frequencies are computed from the null hypothesis found in the sample data.The chi-square test is a non-parametric test used to determine the significance of how two or more frequencies are different in a particular population. The non-parametric test means that the distribution is not required to be normal. Instead, this test relies on the sample data and frequency counts.The chi-square test can be used for nominal scale data or categorical data. The observed frequencies for a chi-square test can contain fractions or decimal values. However, the expected frequencies are computed from the null hypothesis found in the sample data. The expected frequencies are the frequencies that are hypothesized for the population being examined. Therefore, option D correctly describes the expected frequencies.
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Find a vector function, r(t), that represents the curve of intersection of the two surfaces. The cone z = x² + y² and the plane z = 2 + y r(t) =
A vector function r(t) that represents the curve of intersection of the two surfaces, the cone z = x² + y² and the plane z = 2 + y, is r(t) = ⟨t, -t² + 2, -t² + 2⟩.
What is the vector function that describes the intersection curve of the given surfaces?To find the vector function representing the curve of intersection between the cone z = x² + y² and the plane z = 2 + y, we need to equate the two equations and express x, y, and z in terms of a parameter, t.
By setting x² + y² = 2 + y, we can rewrite it as x² + (y - 1)² = 1, which represents a circle in the xy-plane with a radius of 1 and centered at (0, 1). This allows us to express x and y in terms of t as x = t and y = -t² + 2.
Since the plane equation gives us z = 2 + y, we have z = -t² + 2 as well.
Combining these equations, we obtain the vector function r(t) = ⟨t, -t² + 2, -t² + 2⟩, which represents the curve of intersection.
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Smartphones: A poll agency reports that 80% of teenagers aged 12-17 own smartphones. A random sample of 250 teenagers is drawn. Round your answers to at least four decimal places as needed. Dart 1 n6 (1) Would it be unusual if less than 75% of the sampled teenagers owned smartphones? It (Choose one) be unusual if less than 75% of the sampled teenagers owned smartphones, since the probability is Below, n is the sample size, p is the population proportion and p is the sample proportion. Use the Central Limit Theorem and the TI-84 calculator to find the probability. Round the answer to at least four decimal places. n=148 p=0.14 PC <0.11)-0 Х $
The solution to the problem is as follows:Given that 80% of teenagers aged 12-17 own smartphones. A random sample of 250 teenagers is drawn.
The probability is calculated by using the Central Limit Theorem and the TI-84 calculator, and the answer is rounded to at least four decimal places.PC <0.11)-0 Х $P(X<0.11)To find the probability of less than 75% of the sampled teenagers owned smartphones, convert the percentage to a proportion.75/100 = 0.75
This means that p = 0.75. To find the sample proportion, use the given formula:p = x/nwhere x is the number of teenagers who own smartphones and n is the sample size.Substituting the values into the formula, we get;$$p = \frac{x}{n}$$$$0.8 = \frac{x}{250}$$$$x = 250 × 0.8$$$$x = 200$$Therefore, the sample proportion is 200/250 = 0.8.To find the probability of less than 75% of the sampled teenagers owned smartphones, we use the standard normal distribution formula, which is:Z = (X - μ)/σwhere X is the random variable, μ is the mean, and σ is the standard deviation.
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a bank pays 8 nnual interest, compounded at the end of each month. an account starts with $600, and no further withdrawals or deposits are made.
To calculate the balance in the account after a certain period of time, we can use the formula for compound interest:
[tex]A = P(1 + \frac{r}{n})^{nt}[/tex]
Where:
A = Final amount
P = Principal amount (initial deposit)
r = Annual interest rate (in decimal form)
n = Number of times the interest is compounded per year
t = Time in years
In this case, the principal amount (P) is $600, the annual interest rate (r) is 8% (or 0.08 in decimal form), and the interest is compounded monthly, so the number of times compounded per year (n) is 12.
Let's calculate the balance after one year:
[tex]A = 600(1 + \frac{0.08}{12})^{12 \cdot 1}\\\\= 600(1.00666666667)^{12}\\\\\approx 600(1.08328706767)\\\\\approx 649.97[/tex]
Therefore, after one year, the balance in the account would be approximately $649.97.
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Given the equation y = 7 sin The amplitude is: 7 The period is: The horizontal shift is: The midline is: y = 3 11TT 6 x - 22π 3 +3 units to the Right
The amplitude is 7, the period is 12π/11, the horizontal shift is 22π/33 to the right, and the midline is y = 3, where [11π/6(x - 22π/33)] represents the phase shift.
Given the equation y = 7 sin [11π/6(x - 22π/33)] +3 units to the Right
For the given equation, the amplitude is 7, the period is 12π/11, the horizontal shift is 22π/33 to the right, and the midline is y = 3.
To solve for the amplitude, period, horizontal shift and midline for the equation y = 7 sin [11π/6(x - 22π/33)] +3 units to the right, we must look at each term independently.
1. Amplitude: Amplitude is the highest point on a curve's peak and is usually represented by a. y = a sin(bx + c) + d, where the amplitude is a.
The amplitude of the given equation is 7.
2. Period: The period is the length of one cycle, and in trigonometry, one cycle is represented by one complete revolution around the unit circle.
The period of a trig function can be found by the formula T = (2π)/b in y = a sin(bx + c) + d, where the period is T.
We can then get the period of the equation by finding the value of b and using the formula above.
From y = 7 sin [11π/6(x - 22π/33)] +3, we can see that b = 11π/6. T = (2π)/b = (2π)/ (11π/6) = 12π/11.
Therefore, the period of the equation is 12π/11.3.
Horizontal shift: The equation of y = a sin[b(x - h)] + k shows how to move the graph horizontally. It is moved h units to the right if h is positive.
Otherwise, the graph is moved |h| units to the left.
The value of h can be found using the equation, x - h = 0, to get h.
The equation can be modified by rearranging x - h = 0 to get x = h.
So, the horizontal shift for the given equation y = 7 sin [11π/6(x - 22π/33)] +3 units to the right is 22π/33 to the right.
4. Midline: The y-axis is where the midline passes through the center of the sinusoidal wave.
For y = a sin[b(x - h)] + k, the equation of the midline is y = k.
The midline for the given equation is y = 3.
Therefore, the amplitude is 7, the period is 12π/11, the horizontal shift is 22π/33 to the right, and the midline is y = 3, where [11π/6(x - 22π/33)] represents the phase shift.
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The average selling price of a smartphone purchased by a random sample of 31 customers was $318. Assume the population standard deviation was $30. a. Construct a 90% confidence interval to estimate th
The average selling price of a smartphone is estimated to be $318 with a 90% confidence interval.
a. Constructing a 90% confidence interval requires calculating the margin of error, which is obtained by multiplying the critical value (obtained from the t-distribution for the desired confidence level and degrees of freedom) with the standard error.
The standard error is calculated by dividing the population standard deviation by the square root of the sample size. With the given information, the margin of error can be determined, and by adding and subtracting it from the sample mean, the confidence interval can be constructed.
b. To calculate the margin of error, we use the formula: Margin of error = Critical value * Standard error. The critical value for a 90% confidence level and a sample size of 31 can be obtained from the t-distribution table. Multiplying the critical value with the standard error (which is the population standard deviation / square root of the sample size) will give us the margin of error. Adding and subtracting the margin of error to the sample mean will give us the lower and upper limits of the confidence interval, respectively.
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The correct Question is: The average selling price of a smartphone purchased by a random sample of 31 customers was $318, assuming the population standard deviation was $30. a. Construct a 90% confidence interval to estimate the average selling price.
11.)
12.)
Find the indicated z score. The graph depicts the standard normal distribution with mean 0 and standard deviation 1. The indicated z score is (Round to two decimal places as needed.) A 0.2514, Z 0
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Given the standard normal distribution with a mean of 0 and standard deviation of 1. We are to find the indicated z-score. The indicated z-score is A = 0.2514.
We know that the standard normal distribution has a mean of 0 and standard deviation of 1, therefore the probability of z-score being less than 0 is 0.5. If the z-score is greater than 0 then the probability is greater than 0.5.Hence, we have: P(Z < 0) = 0.5; P(Z > 0) = 1 - P(Z < 0) = 1 - 0.5 = 0.5 (since the normal distribution is symmetrical)The standard normal distribution table gives the probability that Z is less than or equal to z-score. We also know that the normal distribution is symmetrical and can be represented as follows.
Since the area under the standard normal curve is equal to 1 and the curve is symmetrical, the total area of the left tail and right tail is equal to 0.5 each, respectively, so it follows that:Z = 0.2514 is in the right tail of the standard normal distribution, which means that P(Z > 0.2514) = 0.5 - P(Z < 0.2514) = 0.5 - 0.0987 = 0.4013. Answer: Z = 0.2514, the corresponding area is 0.4013.
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characterize the likely shape of a histogram of the distribution of scores on a midterm exam in a graduate statistics course.
The shape of a histogram of the distribution of scores on a midterm exam in a graduate statistics course is likely to be bell-shaped, symmetrical, and normally distributed. The bell curve, or the normal distribution, is a common pattern that emerges in many natural and social phenomena, including test scores.
The mean, median, and mode coincide in a normal distribution, making the data symmetrical on both sides of the central peak.In a graduate statistics course, it is reasonable to assume that students have a good understanding of the subject matter, and as a result, their scores will be evenly distributed around the average, with a few outliers at both ends of the spectrum.The histogram of the distribution of scores will have an approximately normal curve that is bell-shaped, with most of the scores falling in the middle of the range and fewer scores falling at the extremes.
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find the area of the region bounded by the graphs of the equations. y = ex, y = 0, x = 0, and x = 6
Given equations of the region: y = ex y = 0x = 0, and x = 6Now, we have to find the area of the region bounded by the given graphs. So, we can plot these graphs on the coordinate axis and the area can be determined by finding the region's enclosed area.
As we can see from the graph, the region that is enclosed is bounded from x = 0 to x = 6 and y = 0 to y = ex. The area of the enclosed region can be determined as shown below: So, the area of the enclosed region is given as:∫dy = ∫exdx0≤x≤6∫dy = ex(6) - ex(0) = e6 - 1Therefore, the area of the region enclosed is (e^6 - 1) square units. Hence, option (c) is the correct answer.
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Sklyer has made deposits of $680 at the end of every quarter
for 13 years. If interest is %5 compounded annually, how much will
have accumulated in 10 years after the last deposit?
The amount that will have accumulated in 10 years after the last deposit is approximately $13,299.25.
To calculate the accumulated amount, we can use the formula for compound interest:
A = P(1 + r/n)^(nt)
Where:
A = Accumulated amount
P = Principal amount (initial deposit)
r = Annual interest rate (as a decimal)
n = Number of times interest is compounded per year
t = Number of years
In this case, Sklyer has made deposits of $680 at the end of every quarter for 13 years, so the principal amount (P) is $680. The annual interest rate (r) is 5%, which is 0.05 as a decimal. The interest is compounded annually, so the number of times interest is compounded per year (n) is 1. And the number of years (t) for which we need to calculate the accumulated amount is 10.
Plugging these values into the formula, we have:
A = $680(1 + 0.05/1)^(1*10)
= $680(1 + 0.05)^10
= $680(1.05)^10
≈ $13,299.25
Therefore, the amount that will have accumulated in 10 years after the last deposit is approximately $13,299.25.
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Find the mean of the number of batteries sold over the weekend at a convenience store. Round two decimal places. Outcome X 2 4 6 8 0.20 0.40 0.32 0.08 Probability P(X) a.3.15 b.4.25 c.4.56 d. 1.31
The mean number of batteries sold over the weekend calculated using the mean formula is 4.56
Using the probability table givenOutcome (X) | Probability (P(X))
2 | 0.20
4 | 0.40
6 | 0.32
8 | 0.08
Mean = (2 * 0.20) + (4 * 0.40) + (6 * 0.32) + (8 * 0.08)
= 0.40 + 1.60 + 1.92 + 0.64
= 4.56
Therefore, the mean number of batteries sold over the weekend at the convenience store is 4.56.
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HW 3: Problem 17 Previous Problem List Next (1 point) The probability density function of XI, the lifetime of a certain type of device (measured in months), is given by 0 if x ≤21 f(x) = { 21 if x >
The probability density function (PDF) of XI, the lifetime of a certain type of device, is defined as follows:
f(x) = 0, if x ≤ 21
f(x) = 1/21, if x > 21
This means that for any value of x less than or equal to 21, the PDF is zero, indicating that the device cannot have a lifetime less than or equal to 21 months.
For values of x greater than 21, the PDF is 1/21, indicating that the device has a constant probability of 1/21 per month of surviving beyond 21 months.
In other words, the device has a deterministic lifetime of 21 months or less, and after 21 months, it has a constant probability per month of continuing to operate.
It's important to note that this PDF represents a simplified model and may not accurately reflect the actual behavior of the device in real-world scenarios.
It assumes that the device either fails before or exactly at 21 months, or it continues to operate indefinitely with a constant probability of failure per month.
To calculate probabilities or expected values related to the lifetime of the device, additional information or assumptions would be needed, such as the desired time interval or specific events of interest.
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Use a known Maclaurin series to obtain a Maclaurin series for the given function. f(x) = sin (pi x/2) Find the associated radius of convergence R.
The Maclaurin series for [tex]\(f(x) = \sin\left(\frac{\pi x}{2}\right)\)[/tex] is given by:
[tex]\[\sin\left(\frac{\pi x}{2}\right) = \frac{\pi}{2} \left(x - \frac{\left(\pi^2 x^3\right)}{2^3 \cdot 3!} + \frac{\left(\pi^4 x^5\right)}{2^5 \cdot 5!} - \frac{\left(\pi^6 x^7\right)}{2^7 \cdot 7!} + \ldots\right).\][/tex]
The radius of convergence, [tex]\(R\)[/tex] , for this series is infinite since the series converges for all real values of [tex]\(x\).[/tex]
Therefore, the Maclaurin series for [tex]\(f(x) = \sin\left(\frac{\pi x}{2}\right)\)[/tex] is:
[tex]\[\sin\left(\frac{\pi x}{2}\right) = \frac{\pi}{2} \left(x - \frac{\left(\pi^2 x^3\right)}{2^3 \cdot 3!} + \frac{\left(\pi^4 x^5\right)}{2^5 \cdot 5!} - \frac{\left(\pi^6 x^7\right)}{2^7 \cdot 7!} + \ldots\right)\][/tex]
with an associated radius of convergence [tex]\(R = \infty\).[/tex]
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find all solutions of the equation cos x sin x − 2 cos x = 0 . the answer is a b k π where k is any integer and 0 < a < π ,
Therefore, the only solutions within the given interval are the values of x for which cos(x) = 0, namely [tex]x = (2k + 1)\pi/2,[/tex] where k is any integer, and 0 < a < π.
To find all solutions of the equation cos(x)sin(x) - 2cos(x) = 0, we can factor out the common term cos(x) from the left-hand side:
cos(x)(sin(x) - 2) = 0
Now, we have two possibilities for the equation to be satisfied:
cos(x) = 0In this case, x can take values of the form x = (2k + 1)π/2, where k is any integer.
sin(x) - 2 = 0 Solving this equation for sin(x), we get sin(x) = 2. However, there are no solutions to this equation within the interval 0 < a < π, as the range of sin(x) is -1 to 1.
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