Reference no: EM132922017

Question 1:

An alumni association wants to estimate the mean debt of this year's college graduates. It is known that the population standard deviation of the debts of this year's college graduates is $11,800. How large a sample should be selected so that the estimate with a 99% confidence level is within $800 of the population mean?

Question 2:

Determine the sample size for the estimate of μ for the following

I. E = 2.3, σ = 15.40, confidence level = 99%

II. E = 4.1, σ = 23.45, confidence level = 95%

III. E = 25.9, σ = 122.25, confidence level = 90%

Question 3:

Sixty-four randomly selected adults who buy books for general reading were asked how much they usually spend on books per year. The sample produced a mean of $1450 and a standard deviation of $300 for such annual expenses. Determine a 99% confidence interval for the corresponding population mean.