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3 years ago

9

Bill earns 12$ per hr

1 answer:

garik1379 [7]3 years ago

3 0

Answer:

dang nice

Step-by-step explanation:

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Fabienne rolls a ball 72 inches across the floor. This is 9 times the distance that Olivier rolls his ball across the floor. Let

RoseWind [281]

Answer:

8 inches

Step-by-step explanation:

Oliver rolls his ball 1/9th of the distance Fabienne rolls his, so just divide 72 by 9 to get your answer.

8 0

3 years ago

Read 2 more answers

A simple random sample of items resulted in a sample mean of . The population standard deviation is . a. Compute the confidence

Varvara68 [4.7K]

Answer:

(a): The 95% confidence interval is (46.4, 53.6)

(b): The 95% confidence interval is (47.9, 52.1)

(c): Larger sample gives a smaller margin of error.

Step-by-step explanation:

Given

$n = 30$ -- sample size

$\bar x = 50$ -- sample mean

$\sigma = 10$ --- sample standard deviation

Solving (a): The confidence interval of the population mean

Calculate the standard error

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {30}}$

$\sigma_x = \frac{10}{5.478}$

$\sigma_x = 1.825$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.825$

$E = 3.577$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 3.577$

$Lower = 46.423$

$Lower = 46.4$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 3.577$

$Upper = 53.577$

$Upper = 53.6$ --- approximated

<em>So, the 95% confidence interval is (46.4, 53.6)</em>

Solving (b): The confidence interval of the population mean if mean = 90

First, calculate the standard error of the mean

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {90}}$

$\sigma_x = \frac{10}{9.49}$

$\sigma_x = 1.054$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.054$

$E = 2.06584$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 2.06584$

$Lower = 47.93416$

$Lower = 47.9$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 2.06584$

$Upper = 52.06584$

$Upper = 52.1$ --- approximated

<em>So, the 95% confidence interval is (47.9, 52.1)</em>

Solving (c): Effect of larger sample size on margin of error

In (a), we have:

$n = 30$ $E = 3.577$

In (b), we have:

$n = 90$ $E = 2.06584$

<em>Notice that the margin of error decreases when the sample size increases.</em>

4 0

3 years ago

Chocolate candy bars cost $2.00 each. If sales tax is 9%, what is the final price of three candy bars?

Tcecarenko [31]

$6.54 is the final price of the candy bars

5 0

3 years ago

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Find the Y intercept.<br><br> X Y<br> -3 0<br> 0 2<br> 3 4<br> -6 -2<br> 6 6<br><br><br> b= ___

nadya68 [22]

Answer:

noooooo seeeeeeeeeeee

3 0

3 years ago

Professor Andrews found that as the number of days absent increases, students' grades decrease. Professor Andrews has found:

n200080 [17]

Answer:

The function relating student absent days to grades has a negative slope (grades decrease as absences increase).

Step-by-step explanation:

There isn't much information in the question, but here are a couple of observations. Prof. Andrews found:

The function relating student absent days to grades has a negative slope (grades decrease as absences increase).
Evidence suggesting his lectures do convey useful information
Students don't enjoy his class

Just kidding on the last 2, but all statements could be valid based on what little information is provided.

3 0

2 years ago