Question

A)Assume that a sample is used to estimate a population proportion p. Find the 90% confidence interval for a sample of size 157 with 54 successes. Enter your answer as an open-interval (i.e., parentheses) using decimals (not percents) accurate to three decimal places. C.I. =

B) Assume that a sample is used to estimate a population proportion p. Find the 99.9% confidence interval for a sample of size 142 with 65 successes. Enter your answer as a tri-linear inequality using decimals (not percents) accurate to three decimal places. ______ < p < _______

C) We wish to estimate what percent of adult residents in a certain county are parents. Out of 600 adult residents sampled, 390 had kids. Based on this, construct a 90% 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 = ___ ± ___

D) Out of 200 people sampled, 132 had kids. Based on this, construct a 90% confidence interval for the true population proportion of people with kids. Give your answers as decimals, to four places
____ < p < ____

Answer 1

Solution:

A)

B)

C)

D)