Researchers conducted a study to determine whether magnets are effective in treating back pain. Pain was measured using the visual analog scale, and the results
shown below are among the results obtained in the study. Higher scores correspond to greater pain levels. Assume that the two samples are independent simple
random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Complete parts (a) to (c)
below.
Reduction in Pain Level After Magnet Treatment (₂): n=21, x=0.42, s= 0.98
Reduction in Pain Level After Sham Treatment (₂): n=21, x=0.39, s = 1.23
a. Use a 0.01 significance level to test the claim that those treated with magnets have a greater mean reduction in pain than those given a sham treatment (similar
to a placebo).
What are the null and alternative hypotheses?