Weights of women in one age group are normally distributed

Weights of women in one age group are normally distributed with a standard deviation s of 17 lbs. A researcher wants to estimate the mean weight of all women in this age group. Find how large a sample must be drawn in order to be 90% confident that the sample mean will not differ from the population mean by more than 3.5 lbs. Hint: Here, 3.5 is the Margin of Error. Determine the required sample size for estimating the population mean as presented in a formula in Chapter 8.3)Answer ? A.as large as possible ? ? B.76 ? ? C.65 ? ? D.
Document Preview:
Weights of women in one age group are normally distributed with a standard deviation s of 17 lbs. A researcher wants to estimate the mean weight of all women in this age group. Find how large a sample must be drawn in order to be 90% confident that the sample mean will not differ from the population mean by more than 3.5 lbs. Hint: Here, 3.5 is the Margin of Error. Determine the required sample size for estimating the population mean as presented in a formula in Chapter 8.3)Answer ? A.as large as possible ? ? B.76 ? ? C.65 ? ? D.91 ? The principal of a middle school claims that test scores of seventh-graders at her school vary less than test scores of seventh-graders at a neighboring school whose variation is described by a standard deviation of s = 14.7. Identify the null hypothesis, H0 and the alternative hypothesis Ha using s for a claim about variation. Answer ? A.H0: s > 14.7 H1: s = 14.7? ? B.H0: s 14.7? ? C.H0: s = 14.7 H1: s > 14.7? ? D.H0: s = 14.7 H1: s ? The manufacturer of a refrigerator system for beer kegs produces refrigerators that are supposed to maintain a true mean temperature, µ, of 46° F, ideal for a certain type of German pilsner. The owner of the brewery does not agree with the refrigerator manufacturer, and claims he can prove the true mean temperature is incorrect. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is to reject the null hypothesis, state the conclusion in nontechnical terms. Answer ? A.There is sufficient evidence to support the claim that the mean temperature is different from 46°F. ? ? B.There is not sufficient evidence to support the claim that the mean temperature is different from 46°F. ? ? C.There is not sufficient evidence to support the claim that the mean temperature is equal to 46°F. ? ? D.There is sufficient evidence to support the claim that the mean temperature is equal to 46°F. ? An article in a scientific.