Using the Birth Weight data set,

(a) estimate the percentage of low birth weight babies for mothers who smoked during pregnancy (????S).

(b) estimate the percentage of low birth weight babies for mothers who did not smoke during pregnancy (????N).

(c) test ????0 ∶ ????S ≤ ????N at the ???? = 0.05 level.

(d) compute a 95% confidence interval for ????S − ????N.