Chapter 9.4, Problem 1LC

A new over-the-counter cold medication includes a warning label stating that it “may cause drowsiness.” A researcher would like to evaluate this effect. It is know n that under regular circumstances the distribution of reaction times is normal with $\mu$ = 200. A sample of n = 9 participants is obtained. Each person is given the new cold medication, and. 1 hour later, reaction time is measured for each individual. The average reaction time for this sample is M = 206 with SS = 648. The researcher would like to use a hypothesis test with $\alpha$ = .05 to evaluate the effect of the medication.

a. Use a two-tailed test with $\alpha$ = .05 to determine whether the medication has a significant effect on reaction time.

b. Write a sentence that demonstrates how the outcome of the hypothesis test would appear in a research report.

c. Use a one-tailed lest with $\alpha$ = .05 to determine whether the medication produces a significant increase in reaction time.

d. Write a sentence that demonstrates how the outcome of the one-tailed hypothesis test would appear in a research report.