# solution

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. Your company sells exercise clothing and equipment on the Internet. To design the clothing, you collect data on the physical characteristics of your different types of customers. Here are the weights for a sample of 24 male runners. Assume that these runners can be viewed as a random sample of your potential customers. The weights are expressed in kilograms. DATADATA

DATA FILE

CLOTHING

68.7Â Â  Â 61.8Â Â  Â 63.2\$1rn Â 53.1\$1rn Â 62.3\$1rn 59.7\$1rn 55.4\$1rn 58.9\$1rn Â Â 60.9\$1rn Â 69.2\$1rn Â Â 63.7\$1rn Â Â 67.8

65.6\$1rn 65.5Â  Â 56.0\$1rn 57.8\$1rn Â 66.0\$1rn Â 62.9\$1rn 53.6 Â Â Â 65.0\$1rn Â Â Â 55.8\$1rn Â Â Â 60.4\$1rn Â 69.3\$1rn Â 62.1

Exercise 6.24 (page 350) asks you to find a 95% confidence interval for the mean weight of the population of all such runners,

assuming that the population standard deviation is Ïƒ = 4.5 kg.

(a) Give the confidence interval from that exercise, or calculate the interval if you did not do the exercise.

(b) Based on this confidence interval, does a test of

H0: Î¼ = 61.3 kg

Ha: Î¼ _= 61.3 kg

reject H0 at the 5% significance level?

(c) Would H0: Î¼ = 63 be rejected at the 5% level if tested against a two-sided alternative?

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