Question

According to the Centers for Disease Control (CDC), 15.2% of American adults experience migraine headaches. Stress is a major contributor to the frequency and intensity of headaches. A massage therapist feels that she has a technique that can reduce the frequency and intensity of migraines. A random sample of 500 American adults participate in the massage therapist’s program and 65 report experiencing migraines. Does this sample provide evidence that the proportion of American adults who experience migraines is reduced by the massage therapist’s program? Calculate the test-statistic for a test of Ho: p ≥ 0.152 versus H1: p < 0.152. The test statistic (rounded to 2 decimal places) is ________?

Answer 1