Palmer's Plant Food Company sells two products, Quo-Eco and Quo-Pre, with a sales mix of 65% and 35%, respectively. Quo-Eco has a contribution margin per unit of $10, and Quo-Pre has a contribution margin per unit of $15. The company sold 1,000 total units in March. Requirements: a) Calculate the total contribution margin for the company. b) Assume the sales mix shifted to 50% for each product, and calculate the total contribution margin for the company