Sports and Leisure A random sample of professional wrestlers was obtained, and the annual salary (in dollars) for each was recorded. The summary statistics were x‾ = 47,500 and n = 18. Assume the distribution of annual salary is normal with σ = 8,500.
a. Find a 90% confidence interval for the true mean annual salary for all professional wrestlers.
b. How large a sample is necessary for the bound on the error of estimation to be 3000?
c. How large a sample is necessary for the bound on the error of estimation to be 1000?