19) A sporting goods store determines that the optimal quantity of athletic shoes (in pairs) to order each month is given by the Wilson lot size formula: Q(C, M, s) = 2CM S , where C is the cost (in dollars) of placing an order, M is the number of pairs sold each month, and s is the monthly storage cost (in dollars) per pair of shoes. Find ae as Then find and interpret aQ as (100, 500, 3) Answer: aQ = CM aQ as 2:3 10 , 3 ) as (100, 500, 3) = -30.43; When C = 100, M =500, and s = 3, the optimal quantity decreases by about 30 pairs per order for each dollar increase in the monthly storage cost per pair