solve for x please help (show work!)

Answer:

a. best score to guess would be 33

b. Standard deviation simplifies the square root of the mean so makes it closer to 1 has more consistency as the mean of 32 when squared is sqrt 32  is Class A as class a = 4 and is closer to 5.65685425

as 5.65685425^2 = 32

Step-by-step explanation:

If you are comparing two normally-distributed variables on the same measurement scale then yes, you can regard the standard deviation as an indicator of how reliable the mean is--the smaller the standard deviation, the better able you are to "zero in" on the actual population mean.

a. proofs;

We find  32/6 = 5.333 and 32/5 = 6.4 and 6.4 is closer to both sd 4 and 8 than 5.33 is. As 6.4 it is closer to 6

But when we use 33/6 = 5.5 and therefore shows close range 6

therefore the two sd  proves it is slightly high 32 score average for both classes A + B when joined and high 32 = 33 mean when classes A+B are joined or you could say 32/8 = 4 is class B becomes lower tests scores as 32/4 = 8 of class A that has higher test scores.

In this exercise we have to use probability and statistics to organize the students' grades, so we have:

A) best score is  33

B) Class A

In the first part of the exercise we have to analyze the grades of each class, like this:

A)Class A: 32/4

Class B: 32/8

Dividing each of them we have:

[tex]32/4=8 \\32/8=4[/tex]

B) With the information given above, we can say that the best class is A.

See more about statistics at  brainly.com/question/10951564

Answer:

The ratio between two values A and B is just the quotient between these two values:

ratio = A/B

a) $280 in 7m

Here the ratio is:

$280/7m = $40/m

This also can be read as:

$40 per meter.

b) 105 miles in 2 hours

Here the ratio is:

105mi/2h = 52.5 mi/h

This also can be read as:

52.5 miles per hour

c) $33 for 5lb

The ratio is:

$33/5lb = $6.6/lb

This can be read as:

$6.6 per pound.

d) 50 pages in 2 hours

the ratio is:

(50 pages)/2h = 25 pages/h

this can be read as:

25 pages per hour.

Answer:

A.

Step-by-step explanation:

Each mark is worth two. We are inbetween the first mark and 0 on the left. Half of two is one. and since we are in the left quadrant we know it to be negative. Looking down, we see that we are exactly one mark down. As a mark is two, ans that we are going down, this will be a negative two. That leaves us with the answer of (-1, -2)

Answer:

A. (-1,-2)

Step-by-step explanation:

just trust me...I promise it right

Answer:

2ab

Step-by-step explanation:

7ab+8ab+(-10ab)+(-3ab)=

=15ab-13ab= 2ab

Answer:

2ab

Step-by-step explanation:

7ab+8ab+-10ab+-3ab

Factor out ab

ab(7+8-10-3)

ab(2)

2ab

Answer: See explanation

Step-by-step explanation:

1. Use the five steps of hypothesis testing.

Step 1: The aim of the research is to conduct the five steps of hypothesis testing.

Step 2:

Null hypothesis: H0 u= 4

Population mean: H1 u = 4

Alternate hypothesis: u ≠ 4

Population mean: u ≠ 4

Step 3 and step 4 are attached.

Step 5: Based on the calculation, the calculated value of t is less than the t critical value, therefore, the null hypothesis will be failed to be rejected.

2. Sketch the distributions involved

This has been attached.

3. Explain the logic of what you did to a person who is familiar with hypothesis testing, but knows nothing about t tests of any kind.

The distribution is "t".

The means is tested by using T-test.

Chi-square is used to test the single variance.

Answer:

(in attachment)

Step-by-step explanation:

you can find the points by inputting the x-values into the equation to solve for the y-values, then connecting the plotted points to create the line.

When x=-4

y=1/2(-4)

y=-2

(-4,-2)

Repeat for all values.

Answer:

75

Step-by-step explanation:

For non-normal distributions, we use Chebyshev's Theorem.

Chebyshev Theorem

The Chebyshev Theorem states that:

At least 75% of the measures are within 2 standard deviations of the mean.

At least 89% of the measures are within 3 standard deviations of the mean.

An in general terms, the percentage of measures within k standard deviations of the mean is given by [tex]100(1 - \frac{1}{k^{2}})[/tex].

In this question:

Within 2 standard deviations of the mean, so 75%.

Answer:

x = 5/3  x= -1

Step-by-step explanation:

|3x-1|=4

There are two solutions to the absolute value equation, one positive and one negative

3x-1 =4  and 3x-1=-4

Add 1 to each side

3x-1+1 = 4+1   3x-1+1 = -4+1

3x=5             3x = -3

Divide by 3

3x/3 = 5/3     3x/3 = -3/3

x = 5/3  x= -1

Answer:

28.0125 cm^2 rounded to 28.0 cm^2

Step-by-step explanation:

Area = a*b*sin(c)*1/2

Area = 7 * 13 * sin(38) * 1/2

Area = 91/2 * 0.61566...

Area = 28.0125...

Answer:

The null hypothesis is [tex]H_0: \mu = 444[/tex]

The alternative hypothesis is [tex]H_1: \mu < 444[/tex]

The p-value of the test is 0.1148 > 0.05, which means that the sample does not give enough evidence to conclude that the machine is underfilling the bags.

Step-by-step explanation:

A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 444 gram setting.

At the null hypothesis, we test if the machine works correctly, that is, the mean is of 444. So

[tex]H_0: \mu = 444[/tex]

At the alternative hypothesis, we test if they are underfilling, that is, if the mean is of less than 444. So

[tex]H_1: \mu < 444[/tex]

The test statistic is:

[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, s is the standard deviation and n is the size of the sample.

444 is tested at the null hypothesis:

This means that [tex]\mu = 444[/tex]

A 41 bag sample had a mean of 440 grams with a variance of 441.

This means that [tex]n = 41, X = 440, s = \sqrt{441} = 21[/tex]

Value of the test statistic:

[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]

[tex]t = \frac{440 - 444}{\frac{21}{\sqrt{41}}}[/tex]

[tex]t = -1.22[/tex]

P-value of the test:

Right-tailed test(test if the mean is less than a value), with 41 - 1 = 40 df and t = -1.22.

Using a t-distribution calculator, this p-value is of 0.1148

The p-value of the test is 0.1148 > 0.05, which means that the sample does not give enough evidence to conclude that the machine is underfilling the bags.

Answer:

The p-value of the test statistic is 0.2019.

Step-by-step explanation:

Test if there is evidence at the 0.02 level that the medicine relieves pain in more than 384 seconds.

At the null hypothesis, we test if it relieves pain in at most 384 seconds, that is:

[tex]H_0: \mu \leq 384[/tex]

At the alternative hypothesis, we test if it relieves pain in more than 384 seconds, that is:

[tex]H_1: \mu > 384[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

384 is tested at the null hypothesis:

This means that [tex]\mu = 384[/tex]

For a sample of 41 patients, the mean time in which the medicine relieved pain was 387 seconds. Assume the population standard deviation is 23.

This means that [tex]n = 41, X = 387, \sigma = 23[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{387 - 384}{\frac{23}{\sqrt{41}}}[/tex]

[tex]z = 0.835[/tex]

P-value of the test:

The p-value of the test is the probability of finding a sample mean above 387, which is 1 subtracted by the p-value of z = 0.835.

Looking at the z-table, z = 0.835 has a p-value of 0.7981.

1 - 0.7981 = 0.2019

The p-value of the test statistic is 0.2019.

Answer:

0.9842 = 98.42% probability that at least six of them find employment in their chosen field within three months.

Step-by-step explanation:

For each student, there are only two possible outcomes. Either they found employment, or they did not. The probability of a student finding employment is independent of any other student, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

88% of students who graduate from the university successfully find employment in their chosen field within three months of graduation.

This means that [tex]p = 0.88[/tex]

Nine randomly selected students

This means that [tex]n = 9[/tex]

What is the probability that of nine randomly selected students who have graduated from this university, at least six of them find employment in their chosen field within three months?

This is:

[tex]P(X \geq 6) = P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 6) = C_{9,6}.(0.88)^{6}.(0.12)^{3} = 0.0674[/tex]

[tex]P(X = 7) = C_{9,7}.(0.88)^{7}.(0.12)^{2} = 0.2119[/tex]

[tex]P(X = 8) = C_{9,8}.(0.88)^{8}.(0.12)^{1} = 0.3884[/tex]

[tex]P(X = 9) = C_{9,9}.(0.88)^{9}.(0.12)^{0} = 0.3165[/tex]

Then

[tex]P(X \geq 6) = P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) = 0.0674 + 0.2119 + 0.3884 + 0.3165 = 0.9842[/tex]

0.9842 = 98.42% probability that at least six of them find employment in their chosen field within three months.

Answer:

The p-value of the test is 0.0139 < 0.05, which means that these data indicates that the population proportion of voter turnout in Colorado is higher than that in California.

Step-by-step explanation:

Before testing the hypothesis, 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]

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.

California:

Sample of 296 voters, 146 voted. This means that:

[tex]p_{Ca} = \frac{146}{296} = 0.4932[/tex]

[tex]s_{Ca} = \sqrt{\frac{0.4932*0.5068}{296}} = 0.0291[/tex]

Colorado:

Sample of 215 voters, 127 voted. This means that:

[tex]p_{Co} = \frac{127}{215} = 0.5907[/tex]

[tex]s_{Co} = \sqrt{\frac{0.5907*0.4093}{215}} = 0.0335[/tex]

Test if the population proportion of voter turnout in Colorado is higher than that in California:

At the null hypothesis, we test if it is not higher, that is, the subtraction of the proportions is at most 0. So

[tex]H_0: p_{Co} - p_{Ca} \leq 0[/tex]

At the alternative hypothesis, we test if it is higher, that is, the subtraction of the proportions is greater than 0. So

[tex]H_1: p_{Co} - p_{Ca} > 0[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{s}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error.

0 is tested at the null hypothesis:

This means that [tex]\mu = 0[/tex]

From the two samples:

[tex]X = p_{Co} - p_{Ca} = 0.5907 - 0.4932 =  0.0975[/tex]

[tex]s = \sqrt{s_{Co}^2+s_{Ca}^2} = \sqrt{0.0291^2+0.0335^2} = 0.0444[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{s}[/tex]

[tex]z = \frac{0.0975 - 0}{0.0444}[/tex]

[tex]z = 2.2[/tex]

P-value of the test and decision:

The p-value of the test is the probability of finding a difference above 0.0975, which is 1 subtracted by the p-value of z = 2.2.

Looking at the z-table, z = 2.2 has a p-value of 0.9861.

1 - 0.9861 = 0.0139.

The p-value of the test is 0.0139 < 0.05, which means that these data indicates that the population proportion of voter turnout in Colorado is higher than that in California.

Answer:

◦•●◉these are related functions

Part (a)

If you win $12165, then you really net 12165-35 = 12130 dollars when you consider the ticket fee. So this is the true amount of money you win, or take home at the end of the day. This is before taxes.

Multiply 0.002 with 12,130 to get 0.002*12130 = 24.26

We'll use this later so let A = 24.26

The chances that you don't win are 1 - 0.002 = 0.998 which multiplies with -35 to indicate you lost $35 in playing the game. So we get B = 0.998*(-35) = -34.93

Lastly, add the values of A and B to get the expected value:

A+B = 24.26 + (-34.93) = -10.67 is the expected value.

On average, you expect to lose about $10.67 for any time you play the game.

===========================================================

Part (b)

0.125 is the probability of winning so 1-0.125 = 0.875 is the probability of losing.

Let's say you get really unlucky and lose 12 times in a row. Assuming each trial (aka case when you play the game) is independent, this would mean the probability of such an event is (0.875)^12 = 0.2014172, which is approximate.

Subtract that from 1 to get the probability of winning at least once

1 - (0.875)^12 = 1 - 0.2014172 = 0.7985828

which is also approximate. If we rounded to three decimal places, then it would be 0.799; I'm picking three decimals since 0.125 is to three decimal places. Round however you need to if otherwise.

Answer:

its the 4 one

Step-by-step explanation:

[tex] \underline{ \huge \mathcal{ Ànswér} } \huge: - [/tex]

Average of b and c is 8, that is

[tex]➢ \: \: \dfrac{b + c}{2} = 8[/tex]

[tex]➢ \: \: b + c = 16[/tex]

[tex]➢ \: \: c = 16 - b[/tex]

now let's solve for average of c and d :

[tex]➢ \: \: \dfrac{c + d}{2} [/tex]

[tex]➢ \: \: \dfrac{16 - b + 3b - 4}{2} [/tex]

[tex]➢ \: \: \dfrac{12 + 2b}{2} [/tex]

[tex]➢ \: \: \dfrac{2(6 + b)}{2} [/tex]

[tex]➢ \: \: b + 6[/tex]

Therefore, the average of c and d, in terms of b is : -

[tex] \large \boxed{ \boxed{b + 6}}[/tex]

[tex]\mathrm{✌TeeNForeveR✌}[/tex]

Answer:

b+6

Problem:

If the average of b and c is 8, and d=3b-4, what is the average of c and d in terms of b?

Step-by-step explanation:

We are given (b+c)/2=8 and d=3b-4.

We are asked to find (c+d)/2 in terms of variable, b.

We need to first solve (b+c)/2=8 for c.

Multiply both sides by 2: b+c=16.

Subtract b on both sides: c=16-b

Now let's plug in c=16-b and d=3b-4 into (c+d)/2:

([16-b]+[3b-4])/2

Combine like terms:

(12+2b)/2

Divide top and bottom by 2:

(6+1b)/1

Multiplicative identity property applied:

(6+b)/1

Anything divided by 1 is that anything:

(6+b)

6+b

b+6

Answer:

On average, a player should expect to win $15.

Step-by-step explanation:

The expected value in an event with outcomes:

x₁, x₂, ..., xₙ

Each with probability:

p₁, ..., pₙ

is given by:

Ev = x₁*p₁ + ... +xₙ*pₙ

In this case we have 3 outcomes:

player wins $75 = x₁

player wins $45 = x₂

player does not win = x₃

Let's find the probabilities of these events.

player wins $75)

Here we must have the 3 coins landing on heads, so there is only one possible outcome to win $75

While the total number of outcomes for tossing 3 coins, is the product between the number of outcomes for each individual event (where the individual events are tossing each individual coin, each one with 2 outcomes)

Then the number total of outcomes is:

C = 2*2*2 = 8

Then the probability of winning $75 is the quotient between the number of outcomes to win (only one) and the total number of outcomes (8)

p₁ = 1/8

Win $45:

This happens if the 3 coins land on tails, so is exactly equal to the case above, and the probability is the same:

p₂ = 1/8

Not wining:

Remember that:

p₁ + p₂ + ... + pₙ = 1

Then for this case, we must have:

p₁ + p₂ + p₃ = 1

1/8 + 1/8 + p₃ = 1

p₃ = 1 - 1/8 - 1/8

p₃ = 6/8

Then the expected value will be:

Ev = $75*1/8 + $45*1/8 + $0*6/8 = $15

On average, a player should expect to win $15.

Answer:

[tex]x=216 salads[/tex]

Step-by-step explanation:

One Hour:

Salad=40

Sandwich=19

Total work time[tex]T=7[/tex]

Generally

Time to make 30 sandwiches is

[tex]T_s=\frac{30}{19}[/tex]

[tex]T-s=1.6hours[/tex]

Therefore

Bill has 7-1.6 hours to make salads and can make x about of salads in

[tex]x=(7-1.6)*40[/tex]

[tex]x=5.4*40[/tex]

[tex]x=216 salads[/tex]

Answer:

e. All of the above statements are correct.

Option e is correct. All of the above statements are correct.

Data science is an interdisciplinary academic field that uses statistics, scientific computing, scientific methods, processes, algorithms and systems to extract or extrapolate knowledge and insights from noisy, structured and unstructured data

Data Scientist makes value out of data, he is expert in various tools and technologies like machine learning, deep learning, artificial intelligence and he solve business problems by presenting a model to predict business future.

During data preparation, data scientists and DBAs aggregate the data and merge them from different sources. During data preparation, data scientists and DBAs define the variables to be used in the model.

Hence, All of the above statements are correct, Option e is correct.

To learn more on Data science click:

https://brainly.com/question/20815848

#SPJ5

Answer: the correct answer is D 0.05

Step-by-step explanation:

Answer:

0.02 m/s

Step-by-step explanation:

42/50 meters in 26/30 minutes,

26/30 minutes = 52 seconds

so in 1 second, 42/50 ÷ 52

= 42/50 × 1/52

= 21/1300

= 0.02 (approximately)

Answered by GAUTHMATH

Answer:

B. an infinite number

Step-by-step explanation:

Since point A lies outside of P, the number of lines that can be drawn parallel to P and passing through point A is only infinite. It is infinite because it is just one given point lying outside the plane. If there is more than one point then it will be otherwise.

Answer:

yeah

Step-by-step explanation:

Answer:

C.

Step-by-step explanation:

1) note, the point "а" belongs to the given interval only, then

2) the correct answer is C) a.

Answer:

as we can see here point {\color{Red}a} lies on the interval (-2, -1)

so option A is correct

Step-by-step explanation:

Answer:

Step-by-step explanation:

A relation may or may not represent a function.

Table (a), (c) and (d) represent a function

The tables represent a relation

For a relation to be a function, then:

The y values must have unique (or distinct) x-values.

From the list of tables, we have the following observations

Hence, all the tables represent a valid function, except table (b)

Read more about functions and relations at:

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Answer: hello your question is incomplete attached below is the complete question

answer:

a) Fx(X) = 0 ≤ x ≤ 2,    Fy(Y) = y - y^3/4

b) E(X) = 32/20 ,  E(Y) = 64/60

Step-by-step explanation:

a) Marginal probability density

Fx(X) = [tex]\int\limits^x_0 {\frac{xy}{2} } \, dy[/tex]

∴ probability density of X  = 0 ≤ x ≤ 2

Fy(Y) = [tex]\int\limits^2_y {\frac{xy}{2} } \, dx[/tex]

∴ probability density of Y = y - y^3/4

b) Determine the expected values of X and Y

E(X) = 32/20

E(Y) = 64 /60

attached below is the detailed solution

Answer:

Option C (25%) is the correct answer.

Step-by-step explanation:

Given:

Number of students,

= 120

Students responded high interest,

= 30

Students responded medium interest,

= 50

Students responded low interest,

= 40

Now,

The relative frequency will be:

= [tex]\frac{30}{120}[/tex]

= [tex]0.25[/tex]

or,

= [tex]25[/tex]%

Answer:

[tex] \displaystyle 4[/tex]

Step-by-step explanation:

we are given that A vegetable garden and a surrounding as a shaped like a square that together a 11 ft wide. The path is 2 feet wide.since together the width of Vegetable garden and path is 11 ft, the width of the vegetables garden will be the difference between the total width and the width of path Thus,

[tex] \displaystyle \rm W _{ garden} = 11 - 2[/tex]

simplify substraction:

[tex] \displaystyle \rm W _{ garden} = 9[/tex]

recall that, every single side of a square is equal to each other therefore the the area of the garden will be

[tex] \displaystyle {9}^{2} [/tex]

simplify square:

[tex] \displaystyle 81[/tex]

together the garden and path makes a square of every side length 11 ft saying that the area will be:

[tex] \displaystyle {11}^{2} [/tex]

simplify square:

[tex] \displaystyle 121[/tex]

the area of path will be the difference between the total area and the garden area therefore,

[tex] \displaystyle 121 - 81[/tex]

simplify addition:

[tex] \displaystyle 40[/tex]

to figure out how many bags are needed to cover the path. we just need to divide the area of the path by the area of a bag of gravel and that yields:

[tex] \displaystyle \frac{40}{10} [/tex]

simplify division:

[tex] \displaystyle \boxed{\rm4}[/tex]

hence,

4 bags are needed to cover the path.