Is 83 cm greater than or less than 1 m?

A researcher wants to estimate the percentage of all adults that have used the Internet to seek pre-purchase information in the

Lubov Fominskaja [6]

Answer:

The required sample size for the new study is 801.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

25% of all adults had used the Internet for such a purpose

This means that $\pi = 0.25$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

What is the required sample size for the new study?

This is n for which M = 0.03. So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.03 = 1.96\sqrt{\frac{0.25*0.75)}{n}}$

$0.03\sqrt{n} = 1.96\sqrt{0.25*0.75}$

$\sqrt{n} = \frac{1.96\sqrt{0.25*0.75}}{0.03}$

$(\sqrt{n})^2 = (\frac{1.96\sqrt{0.25*0.75}}{0.03})^2$

$n = 800.3$

Rounding up:

The required sample size for the new study is 801.

4 0

2 years ago

A bus driver started her day with an empty bus. At her first stop she picked up

lidiya [134]

Answer:

12 people.

Step-by-step explanation:

Let's do this one at a time.

First stop:

0 + 11 = 11

Second stop:

11 + 5 = 16.

16 - 7 = 9.

Third stop:

9 + 5 = 14.

14 - 2 = 12.

There were 12 people on the bus after the driver left the third stop.

8 0

2 years ago

If 6 men can do a piece of work in 14 days, how many men are needed to do the work in 21days?

Ivenika [448]

Total work amount
6 men * 14 days
84 men days

If it is done within 21 days, need x men
84 men days = x men * 21 days
x = 84/21 men
x = 4 men

4 0

3 years ago

You are driving on a highway and are about 55 miles from a state border. You set your cruise control at 60 miles per hour and pl

kumpel [21]

Based on your distance from the state border and the cruise control speed, the minimum and maximum hours you will have cruise control on is: