A study was conducted to determine whether an expectant mother's cigarette smoking

has any effect on the bone mineral content of her otherwise healthy child. A sample of 78

newborns whose mothers smoked during pregnancy has mean bone mineral content !=

0.089g/cm and standard deviation ! = 0.022g/cm; a sample of 115 infants whose

mothers did not smoke has mean != 0.083g/cm and standard deviation != 0.023g/cm.

Assume that the underlying population variances are equal.

a. Are the two samples of data paired or independent?

b. State the null and alternative hypotheses of the two-sided test.

c. Conduct the test at the 0.05 level of significance. What do you conclude?