Given a matrix [tex]A[/tex] an element inside a matrix is denoted by [tex]A_{ij}[/tex] where [tex]i[/tex] is a number of a row and [tex]j[/tex] is a number of a column in which the element is in.
Your matrix is called [tex]W[/tex] and it equals to,
[tex]W=\begin{bmatrix}28&21&19\\17&24&15\\22&29&17\\\end{bmatrix}[/tex]
So [tex]W_{11}[/tex] will denote the element in the first row and first column that is [tex]\boxed{W_{11}=28}[/tex].
Hope this helps :)
BRAINLIESTT A spinner is divided into 8 equal-sized sections, and each section is labeled with a number 1 through 8.
if Kathryn spins the arrow on the spinner twice, what is the probability that the arrow will land on a section with an odd number the first time
and a number greater than 6 on the second spln?
Answer:
The probability would be 1/8.
Step-by-step explanation:
The probability of the spinner landing on an odd number is 1/2, and the probability of the spinner landing on a number greater than 8 is 1/4. So we multiply those two probabilites to get our answer 1/8.
If a + b = s and a - b = t, then which of the following expresses the value of ab in terms of s and t?
Please help me out
Answer:
=(s^2 - t^2)/4
Step-by-step explanation:
a + b = s and a - b = t,
Add the two equations together
a + b = s
a - b = t
----------------
2a = s+t
a = (s+t)/2
Subtract the two equations
a + b = s
- a + b = -t
-------------------
2b =(s-t)
b = (s-t)/2
We want to find ab
ab = (s+t)/2 * (s-t)/2
FOIL
=(s^2 - t^2)/4
Consider the following results for two independent random samples taken from two populations.
Sample 1 Sample 2
n1=50 n2=35
x¯1=13.6 x¯2=11.6
σ1=2.2 σ2=3.0
Required:
a. What is the point estimate of the difference between the two population means?
b. Provide a 90% confidence interval for the difference between the two population means.
c. Provide a 95% confidence interval for the difference between the two population means.
Answer:
a. 2
b. The 90% confidence interval for the difference between the two population means is (1.02, 2.98).
c. The 95% confidence interval for the difference between the two population means is (0.83, 3.17).
Step-by-step explanation:
Before solving this question, we need to understand the central limit theorem and the subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Sample 1:
[tex]\mu_1 = 13.6, s_1 = \frac{2.2}{\sqrt{50}} = 0.3111[/tex]
Sample 2:
[tex]\mu_2 = 11.6, s_2 = \frac{3}{\sqrt{35}} = 0.5071[/tex]
Distribution of the difference:
[tex]\mu = \mu_1 - \mu_2 = 13.6 - 11.6 = 2[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.3111^2+0.5071^2} = 0.595[/tex]
a. What is the point estimate of the difference between the two population means?
Sample difference, so [tex]\mu = 2[/tex]
b. Provide a 90% confidence interval for the difference between the two population means.
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.9}{2} = 0.05[/tex]
Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.
The margin of error is:
[tex]M = zs = 1.645(0.595) = 0.98[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is 2 - 0.98 = 1.02
The upper end of the interval is the sample mean added to M. So it is 2 + 0.98 = 2.98
The 90% confidence interval for the difference between the two population means is (1.02, 2.98).
c. Provide a 95% confidence interval for the difference between the two population means.
Following the same logic as b., we have that [tex]Z = 1.96[/tex]. So
[tex]M = zs = 1.96(0.595) = 1.17[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is 2 - 1.17 = 0.83
The upper end of the interval is the sample mean added to M. So it is 2 + 1.17 = 3.17
The 95% confidence interval for the difference between the two population means is (0.83, 3.17).
which choice are equivalent to the expression below? Check all that apply
I could not get the expressions to type correctly because I am new so I am sending a picture. I am having trouble working backwards to figure out which once to choose.
Answer:
A, B, and E apply
Step-by-step explanation:
One thing we can do is to make everything in the same format, under one square root, with no non-square roots.
First, we can say that 6 is equal to √36 as 6² =36, and 6 ≥ 0. Therefore, 6√3 = √36 * √3 = √108
For A, √3 * √36 = √108, so this applies
For B, √18 * √6 = √108, so this applies
For C, 108² = √something bigger than 108 = √11664, so this does not apply
For D, √54 ≠ √108, so this does not apply
For E, √108 = √108, so this applies
For F, √3 * √6 = √18, so this does not apply
Help! Given that tanθ=-1, what is the value of secθ, for 3π/2<θ<2π?
Answer: Choice B) [tex]\sqrt{2}[/tex]
Work Shown:
[tex]\sec^2(\theta) = \tan^2(\theta) + 1\\\\\sec^2(\theta) = (\tan(\theta))^2 + 1\\\\\sec^2(\theta) = (-1)^2 + 1\\\\\sec^2(\theta) = 2\\\\\sec(\theta) = \sqrt{2}\\\\[/tex]
Note: secant is positive in quadrant Q4, when theta is between 3pi/2 radians and 2pi radians (270 degrees and 360 degrees). So that's why we don't consider the minus form of the plus minus.
I really need help big time thank you
PLEASE HELPPPPP ASAPPPPPPPPPPPPP PLEASEEEE
Answer:
0.5679
Step-by-step explanation:
From. The table Given above :
The probability of female Given an advanced degree ;
P(F|A) = p(FnA) / p(A)
From the table, p(FnA) = 322
P(Advanced degree), P(A) = (245 + 322) = 567
Hence,
P(F|A) = p(FnA) / p(A) = 322 / 567 = 0.5679
A BYU-Idaho professor took a survey of his classes and found that 82 out of 90 people who had served a mission had personally met a member of the quorum of the twelve apostles. Of the non-returned missionaries that were surveyed 86 of 110 had personally met a member of the quorum of the twelve apostles. Calculate a 99% confidence interval for the difference in the two proportions.
Answer:
The 99% confidence interval for the difference in the two proportions is (-0.0247, 0.2833).
Step-by-step explanation:
Before building the confidence interval, we need to understand the Central Limit Theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
A BYU-Idaho professor took a survey of his classes and found that 82 out of 90 people who had served a mission had personally met a member of the quorum of the twelve apostles.
This means that:
[tex]p_S = \frac{82}{90} = 0.9111[/tex]
[tex]s_S = \sqrt{\frac{0.9111*0.0888}{90}} = 0.045[/tex]
Of the non-returned missionaries that were surveyed 86 of 110 had personally met a member of the quorum of the twelve apostles.
This means that:
[tex]p_N = \frac{86}{110} = 0.7818[/tex]
[tex]s_N = \sqrt{\frac{0.7818*0.2182}{110}} = 0.0394[/tex]
Distribution of the difference:
[tex]p = p_S - p_N = 0.9111 - 0.7818 = 0.1293[/tex]
[tex]s = \sqrt{s_S^2+s_N^2} = \sqrt{0.045^2+0.0394^2} = 0.0598[/tex]
Calculate a 99% confidence interval for the difference in the two proportions.
The confidence interval is:
[tex]p \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
99% confidence level
So [tex]\alpha = 0.01[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.01}{2} = 0.995[/tex], so [tex]Z = 2.575[/tex].
The lower bound of the interval is:
[tex]p - zs = 0.1293 - 2.575*0.0598 = -0.0247[/tex]
[tex]p + zs = 0.1293 + 2.575*0.0598 = 0.2833[/tex]
The 99% confidence interval for the difference in the two proportions is (-0.0247, 0.2833).
I need help with this
Answer:
below
Step-by-step explanation:
A AND C is the right option
congruent angles are angles with exactly the same measure
help please! i'm in class and i have 10 mins left. :)
Answer:
3:8
Step-by-step explanation:
i will gadit
that only
Factor the trinomial x^2-8x-65
Step-by-step explanation:
here's the answer to your question
A cylindrical piece of iron pipe is shown below. The wall of the pipe is 1.25 inches thick: The figure shows a cylinder of height 14 inches and diameter 8 inches What is the approximate inside volume of the pipe?
332 cubic inches
69 cubic inches
703 cubic inches
99 cubic inches
Answer: 332 cubic inches
Step-by-step explanation:
You can eliminate 69 and 99 as those answers don't make any sense. This leaves you with 703 and 332.
It says the wall of the pipe is 1.25 inches thick so you multiply that by 2 and subtract it by the diameter to get the insider diameter of 5.5
Now you just use the equation V = (3.14)(r^2)(14) where the radius is half of 5.5.
So to finalize the equation you get V = (3.14)(5.5)^2(14) which comes out to 332 cubic inches
The best choice is 332 cubic inches.
69 cubic inches and 99 cubic inches are less and 703 cubic inches is a large approximation.
Diameter = d= 8 inches
Height= Length = l= 14 inches
Thickness= 1.25 inches
Outer Radius= R= diameter/2= 8/2=4 inches
Inner radius = r= Radius - thickness
= 4- 1.25= 2.75 inches
Volume of the cylinder = Area × length
= π r²× l
= 22/7 × (2.75)² × 14
= 332. 616 inches cube
So the best answer is 332 cubic inches
https://brainly.com/question/21067083
Find the midpoint of the line segment with end coordinates of: (-2,-2) and (2,8)
Answer:
(0 ; 3)
Step-by-step explanation:
hello :
the midpoint of the line segment is : ((-2+2)/2 ;(-2+8)/2 )
(0 ; 3)
Consider A Triangle ABC. Suppose That A= 119 Degrees, B=53, And C=57. Solve The Traingle
9514 1404 393
Answer:
a = 94.8, B = 29.3°, C = 31.7°
Step-by-step explanation:
Side 'a' can be found using the Law of Cosines:
a² = b² +c² -2bc·cos(A)
a = √(2809 +3249 -6042·cos(119°)) ≈ √8987.22 ≈ 94.8
Then one of the other angles can be found from the Law of Sines.
sin(C)/c = sin(A)/a
C = arcsin(c/a·sin(A)) ≈ arcsin(0.525874) ≈ 31.7°
Then the remaining angle can be found to be ...
B = 180° -A -C = 180° -119° -31.7° = 29.3°
__
The solution is a ≈ 94.8, B ≈ 29.3°, C ≈ 31.7°.
how many models does the following set have? 5,5,5,7,8,12,12,12,150,150,150
The three modes are 5, 12, and 150 since they occur the most times and they tie one another in being the most frequent (each occurring 3 times).
Only the 7 and 8 occur once each, and aren't modes. Everything else is a mode. It's possible to have more than one mode and often we represent this as a set. So we'd say the mode is {5, 12, 150} where the order doesn't matter.
Please help
4. The equation of a curve is y = (3 - 2x)^3 + 24x.
(a) Find an expression for dy/dx
5. The equation of a curve is y = 54x - (2x - 7)^3.
(a) Find dy/dx
(4) y = (3 - 2x)³ + 24x
Use the power and chain rules:
dy/dx = 3 (3 - 2x)² d/dx [3 - 2x] + 24
dy/dx = 3 (3 - 2x)² (-2) + 24
dy/dx = -24x ² + 72x - 30
(5) y = 54x - (2x - 7)³
Same basic procedure:
dy/dx = 54 - 3 (2x - 7)² d/dx [2x - 7]
dy/dx = 54 - 3 (2x - 7)² (2)
dy/dx = -24x ² + 168x - 240
Find the product :
1) 6/10 × 10/6 × 5/9
2) 6/10 × 4/3 × 10/20
Hello!
1) 6/10 × 10/6 × 5/9 = 1/10 × 10 × 5/9 = 1 × 5/9 = 5/9 or 0,5
2) 6/10 × 4/3 × 10/20 = 6 × 4/3 × 1/20 = 2 × 4 × 1/20 = 2 × 1/5 = 2/5 or 0,4
Good luck! :)
Answer:
1) 5/9
2) 2/5
Explanation:
1) 6/10 × 10/6 × 5/9=
Multiply all the denominators and all the numerators then simplify= 300/540 = 5/9
2) 6/10 × 4/3 × 10/20=
Multiply all the denominators and all the numerators then simplify= 240/600 = 2/5
A line passes through point (5, –3) and is perpendicular to the equation y = x. What's the equation of the line? Question 26 options: a) y = x b) y = –x – 7 c) y = x + 3 d)y = –x + 2
Answer:
sorry my bad bro I have no clue
A recipe calls for 2 1/2 tablespoons of oil and 3/4 tablespoons of vinegar. What is the ratio of oil to vinegar in this recipe?
Answer:
10:3
Step-by-step explanation:
Make 2 1/2 an improper fraction, you will get 5/2. You dont have to do anything to the 3/4.
For you to find the ratio of an fraction, you have to take the numerator but the denominator has to be the same.
So make 5/2 to a 10/4.
Take the numerator 10 & 3.
Your answer will be 10:3
No problem.
Create a sample of 10 numbers that has a mean of 8.6.
Answer:
10 + 8 + 10 + 10 + 10 + 10 + 8 + 8 + 6 + 6
A five-year prospective cohort study has just been completed. The study was designed to assess the association between supplemental vitamin A exposure and mortality and morbidity for measles. The relative risk for incidence of measles was 0.75 and the relative risk for measles mortality was 0.5. Regarding the relative risk, which statement is correct?
a. Exposure to vitamin A appears to protect against morbidity and mortality for measles.
b. Exposure to vitamin A appears to be a risk factor for morbidity and mortality for measles.
c. Exposure to vitamin A is not associated with morbidity and mortality for measles.
d. Exposure to vitamin A is a risk factor for morbidity and a protective factor for mortality for measles.
Answer:
Assessing the association between supplemental vitamin A exposure and mortality and morbidity for measles:
Regarding the relative risk, the correct statement is:
a. Exposure to vitamin A appears to protect against morbidity and mortality for measles.
Step-by-step explanation:
Relative risk for incidence of measles = 0.75
Relative risk for measles mortality = 0.5
Relative risk for mortality and morbidity for measles = 0.375 (0.75 * 0.5)
The combined relative risk is less than 50%
The association is weak because RR is less than 1.
Therefore, there is no association between supplemental vitamin A exposure and mortality and morbidity for measles.
PLEASE HELP AND BE RIGHT BEFORE ANSWERING
9514 1404 393
Answer:
see attached
Step-by-step explanation:
Since point P is the center of dilation, it doesn't move. (It is "invariant.") The other points on the figure move to 1/4 of their original distance from P. On this diagram, it is convenient that the distances are all multiples of 4 units, so dividing by 4 is made easy.
Chau Took 5 3/8 hours to clean the bedroom. Then he took a 1/2 to clean the den. How much total time did he take to clean two rooms.
Answer:
It took Chau 5 hours, 52 minutes, and 30 seconds to clean both rooms.
Step-by-step explanation:
Given that Chau took 5 3/8 hours to clean the bedroom, and then he took a 1/2 to clean the den, to determine how much total time did he take to clean two rooms the following calculation must be performed:
5 + 3/8 + 1/2 = X
5 + 0.375 + 0.5 = X
5.875 = X
0.875 = 7/8
60/8 x 7 = 52.5
Therefore, it took Chau 5 hours, 52 minutes, and 30 seconds to clean both rooms.
To test the effectiveness of a business school preparation course, 8 students took a general business test before and after the course. The results are given below. Exam Score Exam Score Student Before Course (1) After Course (2) 1 530 670 2 690 770 3 910 1,000 4 700 710 5 450 550 6 820 870 7 820 770 8 630 610 If they hope that the prep course is effective in improving the exam scores, what is the alternative hypothesis?
Solution :
Group Before After
Mean 693.75 743.75
Sd 155.37 143.92
SEM 54.93 50.88
n 8 8
Null hypothesis : The preparation course not effective.
[tex]$H_0: \mu_d = 0$[/tex]
Alternative hypothesis : The preparation course is effective in improving the exam scores.
[tex]$H_a : \mu_d>0$[/tex] (after - before)
Simplificar expresiones algebraicas
Solve the following system of equations
x^2+2y^2=59
2x^2+y^2=43
(x ,y), (x, y) (x, y) (x, y)
Answer:
(-3,5),(-3,-5),(3,5),(3,-5)
Step-by-step explanation:
i changed my answer :)
A study conducted by the Center for Population Economics at the University of Chicago studied the birth weights of 614 babies born in New York. The mean weight was 3398 grams with a standard deviation of 892 grams. Assume that birth weight data are approximately bell-shaped. Estimate the number of newborns who weighed between 1614 grams and 5182 grams. Round to the nearest whole number.
Answer:
The number of newborns who weighed between 1614 grams and 5182 grams was of 586.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
The mean weight was 3398 grams with a standard deviation of 892 grams.
This means that [tex]\mu = 3398, \sigma = 892[/tex]
Proportion that weighed between 1614 and 5182 grams:
p-value of Z when X = 5182 subtracted by the p-value of Z when X = 1614.
X = 5182
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{5182 - 3398}{892}[/tex]
[tex]Z = 2[/tex]
[tex]Z = 2[/tex] has a p-value of 0.9772
X = 1614
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{1614 - 3398}{892}[/tex]
[tex]Z = -2[/tex]
[tex]Z = -2[/tex] has a p-value of 0.0228
0.9772 - 0.0228 = 0.9544.
Out of 614 babies:
0.9544*614 = 586
The number of newborns who weighed between 1614 grams and 5182 grams was of 586.
Bob's truck averages 23 miles per gallon. If Bob is driving to his mother's house, 72 miles away, how many gallons of gas are needed? Round to the nearest tenth.
Answer:
3.1 gallons
Step-by-step explanation:
To solve this, we need to figure out how many gallons of gas go into 72 miles. We know 23 miles is equal to one gallon of gas, and given that the ratio of miles to gas stays the same, we can say that
miles of gas / gallons = miles of gas / gallons
23 miles / 1 gallon = 72 miles / gallons needed to go to Bob's mother's house
If we write the gallons needed to go to Bob's mother's house as g, we can say
23 miles / 1 gallon = 72 miles/g
multiply both sides by 1 gallon to remove a denominator
23 miles = 72 miles * 1 gallon /g
multiply both sides by g to remove the other denominator
23 miles * g = 72 miles * 1 gallon
divide both sides by 23 miles to isolate the g
g = 72 miles * 1 gallon/23 miles
= 72 / 23 gallons
≈ 3.1 gallons
What are the zeros of f(x) = (x - 2)(x + 7)? Select all that apply.
A. X= -7
B. X = -2
C. X = 2
D. X = 7
Answer:
2 = x -7 = x
Step-by-step explanation:
f(x) = (x - 2)(x + 7)
y = (x - 2)(x + 7)
Set y = 0
0 = (x - 2)(x + 7)
Using the zero product property
0 = x-2 0 = x+7
2 = x -7 = x
Answer:
Zeros happen when f(x) = 0. There are two zeros in the given function:
when (x - 2) = 0when (x + 7) = 0Therefore solve both equations above and you'll get:
Zero #1 = 2Zero #2 = -7What is the chance of getting 3 of the same cards in a row in a 52 cards deck?
Answer:
1/425
Step-by-step explanation:
The first card can be any card, so we don’t have to evaluate the probability.
Now we can suppose that the exit card is a two
- For the second card we have 3/51 of possibilities that is a 2 = 1/17
- For the third card we have 2/50 of possibilities that is a 2 = 1/25
1/17 * 1/25 = 1/425