Concert Tours. In Exercise 8.74, you found a 99% confidence interval of 474515.21 tickets to 685132.79 tickets for the mean number of tickets sold of top 30 concerts.

a. Determine the margin of error, E.

b. Explain the meaning of E in this context in terms of the accuracy of the estimate.

c. Find the sample size required to have a margin of error of 300,000 tickets and a 95% confidence level. (Recall that σ = 224000 tickets.)

d. Obtain a 95% confidence interval for the mean gross sale if a sample of the size determined in part

(c) has a mean of 600,000 tickets.