In a study of maternal cigarette smoking and bone density in newborns, 77 infants of mothers who smoked has a mean bone mineral content of 0.098 g/cm3 (s1 = 0.026 g/cm3). The 161 infants whose mothers did not smoke has a mean bone mineral content of 0.095 g/cm3 (s2 = 0.025 g/cm3).
a) Calculate the 95% confidence interval for µ1 - µ2.
b) Based on the confidence interval you just calculated, would you reject or retain H0: µ1 - µ2 = 0 at α=0.05?