91Ó°ÊÓ

Given in the question that, the confidence interval is $0.4-0.7$ we have to identify the educated guess that should be used for the observed value of $\hat{p}$ to calculate the required sample size for a prescribed confidence level and margin of error.

The educated prediction is the value that is closest to the midpoint of the expected range of $0.4-0.7$dollars. As a result, $0.4$ is the educated estimation for the sample proportion.

Given in the question that, the confidence interval is $0.4-0.7$we have to

Identify the observed values of the sample proportion that will yield a larger margin of error than the one specified if the educated guess is used for the sample-size computation.

A bigger margin of error is provided by the value range of $0.4-0.7$. As a result, the observed sample proportion values vary from $0.4-0.7$. That is, $0.4<\hat{p}<0.7$.