Assignment:
Hypothesis Test of Equal Variances. In Exercises 1 and 2, test the given claim. Use a significance level of α = 0.05 and assume that all populations are normally distributed.
1. Zinc Treatment Claim: Weights of babies born to mothers given placebos vary more than weights of babies born to mothers given zinc supplements (based on data from "The Effect of Zinc Supplementation on Pregnancy Outcome," by Goldenberg, et al., Journal of the American Medical Association, Vol. 274, No. 6). Sample results are summarized below.
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Placebo group:
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n = 16,  = 3088 g, s = 728 g
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Treatment group:
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n = 16, = 3214 g, s = 669 g
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2. Weights of Pennies Claim: Weights of pre-1983 pennies and weights of post-1983 pennies have the same amount of variation. (The results are based on Data Set 20 in Appendix B.)
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Weights of pre-1983 pennies:
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n = 35, = 3.07478 g, s = 0.03910 g
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Weights of post-1983 pennies:
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n = 37, = 2.49910 g, s = 0.01648 g
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