a. A zoologist on safari is able to capture and release 40 male African lions. The average weight of the lions was 438 pounds with standard deviation of 27.3 pounds. Using this data, find the 90% confidence interval for the average weight of all African lions. Round to 1 decimal place. Show your work.
b.
Chris is going to start a roofing company and want to be sure he charges his customers a competitive rate. To accomplish this, he gets 11 bids from local roofing companies for a 2000 square-foot roof. The average cost for a roof from the bids was $4,500 with standard deviation of $750. Find the 95% confidence interval for the average cost for a 2000 sq-ft roof. Round answer to nearest dollar. Show your work.
What do you think would be a good price for Chris to charge for a 2000 sq-ft roof?