Acupuncture and pregnancy A study reported in the medical journal Fertility and Sterility sought to determine whether the ancient Chinese art of acupuncture could help infertile women become pregnant.18 One hundred sixty healthy women who planned to have IVF were recruited for the study.

Half of the subjects (80) were randomly assigned to receive acupuncture 25 minutes before embryo transfer and again 25 minutes after the transfer. The remaining 80 women were assigned to a control group and instructed to lie still for 25 minutes after the embryo transfer. Results are shown in the table below.

Acupuncture group Control group Pregnant 34 21 Not pregnant 46 59 Total 80 80 Is the pregnancy rate significantly higher for women who received acupuncture? To find out, researchers perform a test of H0: p1 = p2 versus Ha: p1 > p2, where p1 and p2 are the actual pregnancy rates for women like those in the study who do and don’t receive acupuncture, respectively.

(a) Name the appropriate test and check that the conditions for carrying out this test are met.

(b) The appropriate test from part

(a) yields a P-value of 0.0152. Interpret this P-value in context.

(c) What conclusion should researchers draw at the a = 0.05 significance level? Explain.

(d) The women in the study knew whether or not they received acupuncture. Explain why this is important.