A random sample of the birth weights of 186 babies has a mean of 3103 g and a standard deviation of 696 g.
These babies were born to mothers who did not use cocaine during their pregnancies.
a. Construct a 95% confidence interval estimate of the mean birth weight for all such babies.
b. Compare the result to the confidence interval of 2607.724 < μ < 2792.276 for the birth weights of babies born to mothers who used cocaine during pregnancy.
c. Does cocaine use appear to affect the birth weight of a baby?