Answers for #8

8. In 1990, the mean height of women 20 years of age or older was 63.7 inches based on data obtained from the CDC's "Advanced Data Report", No. 347. Suppose that a random sample of 38 women who are 20 years of age or older today results in a mean height of 63.9 inches with a standard deviation of 1.37 inches. Is there evidence to suggest that women today are taller? Use the rejection region method a) State HO, Ha. b ) State the test you will use. (z-test, t-test, 1-prop-Ztest, etc) c) Sketch your rejection region and label the cutoff(s). d) Calculate your test statistic (from calculator). e) State your decision. f) Interpret your decision in terms of the original