The length of human pregnancy is known to have a mean of 266 days

and a standard deviation of 16 days. Based on records from a large women’s hospital, a random sample of 25 women who were smoking and/or drinking alcohol during their pregnancy and their pregnancy lengths are recorded in the data file linked below. Do the data provide enough evidence to support the (well-known) fact that women who smoke and/or drink alcohol during their pregnancy have shorter pregnancies than women in general (in other words, are more likely to have premature labor)?


It is reasonable to assume that the known standard deviation of 16 days applies also to women who smoke and/or drink during their pregnancy.

Download the data here:

  • Excel: [LINK]
  • Text: [LINK]

1) State the null and alternative hypotheses, and define clearly what the parameter μ represents

2) Have the conditions that allow us to safely use the z-test been met? Support your answer with appropriate graphs, if needed.

3)Compute the test statistic (use z Compute the test statistic )and interpret its value1. Given that the tabulation meon M= 266 dy’sandpopulation " standard deviation = 6′ = 16 daysandSample Size = n= 25D state the null and alternate by pothesisHere Me representstheNull…

"Get 15% discount on your first 3 orders with us"
Use the following coupon

Order Now