The Steak and Chop Butcher Shop purchases steak from a local meatpacking house. The meat is purchased on Monday at $2.00 per pound, and the shop sells the steak for $3.00 per pound. Any steak left over at the end of the week is sold to a local zoo for $.50 per pound. The possible demands for steak and the probability of each are shown in the following table:

The shop must decide how much steak to order in a week. Construct a payoff table for this decision situation, and determine the amount of steak that should be ordered, using expected value.

I don't understand which formulas to use. I need some guidance through the formulas in the Excel.