# Question: Referring to Exercise 8 12b page 299 assume that the population

Referring to Exercise 8.12b (page 299), assume that the population standard deviation equals .66. How large a sample of late replacement buyers is needed to make us?

In exercise Suppose that a random sample of 500 late replacement buyers yields a mean number of dealers visited equal to 4.3, and assume that the population standard deviation equals .66. Calculate a 99 percent confidence interval for the population mean number of dealers visited by all late replacement buyers.

a. 99 percent confident that the sample mean number of dealers visited, is within a margin of error of .04 of m, the population mean number of dealers visited?

b. 99.73 percent confident that is within a margin of error of .05 of μ?

In exercise Suppose that a random sample of 500 late replacement buyers yields a mean number of dealers visited equal to 4.3, and assume that the population standard deviation equals .66. Calculate a 99 percent confidence interval for the population mean number of dealers visited by all late replacement buyers.

a. 99 percent confident that the sample mean number of dealers visited, is within a margin of error of .04 of m, the population mean number of dealers visited?

b. 99.73 percent confident that is within a margin of error of .05 of μ?

## Answer to relevant Questions

Referring to Exercise 8.21 (page 307), regard the sample of five trial runs (which has standard deviation 19.65) as a preliminary sample. Determine the number of trial runs of the chemical process needed to make us: In ...In each of the following cases, determine whether the sample size n is large enough to use the large sample formula presented in the box on page 311 to compute a confidence interval for p. a. p̂ = .1, n = 30 b. p̂ = .1, ...The manufacturer of the ColorSmart-5000 television set claims 95 percent of its sets last at least five years without needing a single repair. In order to test this claim, a consumer group randomly selects 400 consumers who ...In an article in the Journal of Accounting Research, Ashton, Willingham, and Elliott studied audit delay (the length of time from a company’s fiscal year-end to the date of the auditor’s report) for industrial and ...The mean of the sample of 65 customer satisfaction ratings in Table 1.7 is 42.95. If we let m denote the mean of all possible customer satisfaction ratings for the XYZ Box video game system, and assume that the population ...Post your question