June Wade has invested in two startup companies. At the end of the first year, she asks you to evaluate their operating performance. The following operating data apply to the first year. Required a. Use the contribution margin approach to compute the operating leverage for each firm. b. If the economy expands in the coming year, Cook and Penn will both enjoy a 10 percent per year increase in sales volume, assuming that the selling price remains unchanged. (Note: Since the number of units increases, both revenue and variable cost will increase.) Compute the change in net income for each firm in dollar amount and in percentage. c. If the economy contracts in the following year, Cook and Penn will both suffer a 10 percent decrease in sales volume, assuming that the selling price remains unchanged. (Note: Since the number of units decreases, both revenue and variable cost decrease.) Compute the change in net income for each firm in both dollar amount and percentage. d. Write a memo to June Wade with your evaluation and recommendations