Question

1. We wish to estimate what percent of adult residents in a certain county are parents. Out of 400 adult residents sampled, 296 had kids. Based on this, construct a 95% confidence interval for the proportion p of adult residents who are parents in this county. Express your answer in tri-inequality form. Give your answers as decimals, to three places.

__< p <__ Express the same answer using the point estimate and margin of error. Give your answers as decimals, to three places.

p =__ ±±____

2.

Giving a test to a group of students, the grades and gender are summarized below

	A	B	C	Total
Male	14	8	15	37
Female	13	18	12	43
Total	27	26	27	80

Let p represent the population proportion of all female students who received a grade of C on this test. Use a 95% confidence interval to estimate p to four decimal places if possible.
___< p < ____

3. Assume that a sample is used to estimate a population proportion p. Find the 99% confidence interval for a sample of size 308 with 136 successes. Enter your answer as an open-interval (i.e., parentheses) using decimals (not percents) accurate to three decimal places.
C.I. =_____

4. Assume that a sample is used to estimate a population proportion p. Find the 90% confidence interval for a sample of size 276 with 36% successes. Enter your answer as a tri-linear inequality using decimals (not percents) accurate to three decimal places.
__ < p <___

Answer 1