) David also sells cakes at the store. Assume the cakes retail at $5 per cake, but David only pays $2 per cake. Cakes cannot be sold after one week, and they have a negligible salvage value. David estimates that the weekly demand for cakes is: 15 cakes in 10% of the weeks, 16 cakes in 20% of the weeks, 17 cakes in 25% of the weeks, 18 cakes in 20% of the weeks, 19 cakes in 15% of the weeks, and 20 cakes in 10% of the weeks. How many cakes should David order