Question: A study was conducted of pregnant women who smoked and those who did not smoke, to see if maternal smoking had an effect on the birth weight. At the .05 level, test the claim that maternal smoking can lower the birth weight of a child. Assume the variances to be equal.

Smokers Non-smokers

n1 = 10 n 2 = 10

1 x = 6.9 2 x = 7.2

s1 = .5 s 2 = .4