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3 years ago

9

luna wants to know what proportion of 7th graders at her school are interested in taking art classes.which Is the best group to

survey to find this information?

2 answers:

xeze [42]3 years ago

7 0

Answer: Ask every 12th person who leaves school one afternoon.

Roll dice to determine which person to ask first.

Sati [7]3 years ago

3 0

Answer: Ask every 12th person who leaves school one afternoon.

Roll dice to determine which person to ask first.

Step-by-step explanation:

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Find the area of the shaded region

Andre45 [30]

Answer:

13.73 ft²

or 14 ft² if youre rounding

Step-by-step explanation:

area of circle:

A≈50.27

area of the square:

A = 64

subtract the area of the circle from the area of the square

64 - 50.27

= 13.73 , or 14 if you round it

7 0

4 years ago

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How many solutions are there to the equation below 14x+2=12x

Veronika [31]

The answer is x-1 hope that helps not sure if it does

8 0

3 years ago

An isosceles trapezoid is a trapezoid with congruent legs.<br>A. True<br>B. False

Shalnov [3]

The anwser is false

7 0

3 years ago

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

Between the time Iko woke up and lunchtime,the temperature rose by 11°.Then by the time he went to bed,the temperature dropped b

natali 33 [55]

Answer: Cannot be done

Step-by-step explanation:

This is impossible as there is no previous information and we don’t have a formula.

7 0

3 years ago

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