eBay. An Australian collector has purchased a certain quantity of cricket cards and is going to sell them on eBay.

He has 19 Ashes Cricket Card sets. In recent auctions, the mean selling price of such cards is AUD $12.11, with a standard deviation of AUD $1.38. He also has 13 Australian Champion Cricketers autographed index cards which have had a mean selling price of AUD $10.19, with a standard deviation of AUD $0.77. His insertion fee will be AUD $0.55 on each item, and the closing fee will be 8.75% of the selling price. He assumes all will sell without having to be relisted.

a) Define your random variables. Use them to create a random variable for the collector’s net revenue.

b) Find the mean (expected value) of the net revenue.

c) Find the standard deviation of the net revenue.

d) Do you have to assume independence for the sales on eBay? Explain.