Babies Weighing Less Than 5 A Develop a 95% Confidence Interval Estimate for the Difference

Short Answer

Babies weighing less than 5.5 pounds at birth are considered "low­birth­weight babies." In the United States, 7.6% of newborns are low-birth-weight babies. The following information was accumulated from samples of new births taken from two counties.
$\begin{array}{lcc}&\text { Hamilton }&\text { Shelby }\\\text { Sample size } & 150 & 200 \\\text { Number of "low-birth-weight babies } & 18 & 22\end{array}$

a. Develop a 95% confidence interval estimate for the difference between the proportions of low-birth-weight babies in the two counties.
b. Is there conclusive evidence that one of the proportions is significantly more than the other? If yes, which county? Explain, using the results of part a). Do not perform any test.