Gestational length, African American women, hypothesis test.

Studies in the general population suggest that the gestational length of uncomplicated pregnancies varies according to a Normal distribution with μ = 39 weeks with σ = 2 weeks.e A sample of 22 middle-class African American women demonstrates an average gestation length ( ) of 38.5 weeks. Test whether the mean gestation period in the African American women is significantly different from the expected value of 39 weeks. Use a two-sided alternative hypothesis. Show all hypothesis testing steps.