Assignment:
Assume that both samples are independent simple random samples from populations having normal distributions.
Magnet Treatment of Pain Researchers conducted a study to determine whether magnets are effective in treating back pain, with results given below (based on data from "Bipolar Permanent Magnets for the Treatment of Chronic Lower Back Pain: A Pilot Study," by Collacott, Zimmerman, White, and Rindone, Journal of the American Medical Association, Vol. 283, No. 10). The values represent measurements of pain using the visual analog scale. Use a 0.05 significance level to test the claim that those given a sham treatment (similar to a placebo) have pain reductions that vary more than the pain reductions for those treated with magnets.
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Reduction in pain level after sham treatment:
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n = 20 x = 0.44 s = 1.4
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Reduction in pain level after magnet treatment:
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n = 20 x = 0.49 s = 0.96
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