Posted by **Natasha** on Tuesday, August 17, 2010 at 2:18pm.

2. Assume that the population proportion of adults having a college degree is 0.35. A random sample of 200 adults is to be selected to test this claim.

A) What is the shape, mean, and standard deviation of the sampling distribution of the sample proportion for samples of size 200?

B) What is the probability that the sample proportion will fall within 2% of the population proportion?

C) Answer part B if the sample size were increased to 500 adults. How does the answer to part C differ from part B, and why?

- statistics -
**MathGuru**, Tuesday, August 17, 2010 at 9:39pm
I'll give you a few hints.

Use the approximation to the binomial distribution.

Your values are the following:

p = .35, q = 1 - p = .65, n = 200

Find mean and standard deviation.

mean = np = (200)(.35) = ?

sd = √npq = √(200)(.35)(.65) = ?

Determine two z-scores.

z = -.02/(sd/√n)

z = .02/(sd/√n)

Once you have the z-scores, you should be able to determine the probability between the two z-scores using a z-table.

For part C), just increase the sample size and recalculate.

I hope this will help get you started.

## Answer this Question

## Related Questions

- statistics - The scores of students on the ACT college entrance examination in ...
- statistics - A random sample of 80 youths and a second random sample of 120 ...
- stats - This week we practice with Binomial Distribution. You can use Appendix ...
- Statistics - 1. The scores of students on the ACT college entrance examination ...
- Probability and Statistics - The proportion of adults living in a small town who...
- statistics - Use the given information to find the minimum sample size required ...
- STAT - 1. In a study of the income of U.S. factory workers, a random sample of ...
- Math- Statistics - Suppose 60% of adults have a college degree. If I take a ...
- math - In a large population of adults, the mean IQ is 112 with a standard ...
- Probability and Statistics - The proportion of adults living in a small town who...