Alphabet Custom Products Company produces three different products that all require processing on the same machines. There are only 27,000 machine hours available in each year. Production information for each product is: Required: (1) Determine the preferred sales mix and total contribution margin if there are no market constraints on any of the products. (2) Determine the preferred sales mix and total contribution margin if the demand is limited to 5,000 units for each product. (3) Determine the preferred sales mix and total contribution margin if the demand is limited to 3,000 units for each product