Homework Help: statistics

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: Two Sample Population Confidence Inter - Two Sample Population ...
statistics - According to a survey 35% of adults are against using animals for ...
statistics - Use the given confidence level and sample data to find a confidence...
statistics - The Democrat and Chronicle reported that 25% of the flights ...
statistics - Assume we draw a simple random sample from a population having a ...
statistics - In a survey of 400 college students, 40 were left-handed. Treating ...
statistics - A random sample of 80 youths and a second random sample of 120 ...
Statistics - From random sample of 200 college students, 40 students indicated ...
Statistics - Looking for someone to verify my homework answers on identifying ...

For Further Reading

First Name:
School Subject:
Answer: