Babies weighing less than 5.5 pounds at birth are considered "low-birth-weight 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.
Hamilton Shelby
150 200
Sample size
Number of "low-birth-weight babies" 18 22
Develop a 95% confidence interval estimate for the difference between the proportions of low-birth-weight babies in the two counties.
Is there conclusive evidence that one of the proportions is significantly different from the other