The Central Valley Company is a merchandising firm that sells a single product. The company's revenues and expenses for the last three months are given below:-* AprilMay $735,000 294,000-+' $630,000,, $840,000 +' Less cost of goods sold Less operating expenses: Advertising expense Insurance expense 336,000-+' 252,000+' 378,000- ' 441,000- 504,000 +' 56,000 70,000 143,000- ., 9,000- +' +' 161,75O- +' 9,000. 63,500 70,000 71,000 +' 70,000+'+' 180,500- +' +' Salaries and commissions . 9,000 42,000-42,000* 42,000 +' Total operating expenses. 320,000- 346,250- 372,500--' $58,000* $94,750 $131,500 Required: Determine which expenses are mixed (show computations) and, by use of the high-low method, separate each mixed expense into its variable and fixed components. State the cost formula for each mixed expense.- a. b. Compute the company's total contribution margin (Sales-Variable Costs) for May.+