Data concerning Wislocki Corporation's single product appear below: Fixed expenses are $1,036,000 per month. The company is currently selling 9,500 units per month. Required: The marketing manager would like to introduce sales commissions as an incentive for the sales staff. The marketing manager has proposed a commission of $10 per unit. In exchange, the sales staff would accept an overall decrease in their salaries of $110,000 pe month. The marketing manager predicts that introducing this sales incentive would increase monthly sales by 520 units. What should be the overall effect on the company's monthly net operating income of this change? Fill in the missing amounts in each of the eight case situations below. Each case is independent of the others. (Hint: One way to find the missing amounts would be to prepare a contribution format income statement for each case, enter the known data, and then compute the missing items.) Required: a. Assume that only one product is being sold in each of the following four case situations: b. Assume that more than one product is being sold in each of the following four case situations: (Enter "Contribution margin ratio" in percent. Round your final answers to the nearest whole dollar amount.)