4. Bob's Textile Company sells shirts for men and boys. The average selling price and variable cost for each product are as follows: Men's Selling Price $28.80 Variable Cost $20.40 Bovs Selling Price $24.00 Variable Cost $16.80 Fixed costs are $38,400 Required: a. What is the breakeven point in units for each type of shirt, assuming the sales mix is 2:1 in favor of men's shirts? b. What sales total 9,000 shirts? is the operating income, assuming the sales mix is 2:1 in favor of men's shirts, and