Jake's Roof Repair has provided the following data concerning its costs: Wages and salaries Parts and supplies Equipment depreciation Truck operating expenses Rent Administrative expenses Fixed Cost Cost per per Month Repair-Hour $ 21,000 $ 15.00 $ 7.00 $ 2,750 $ 0.55 $ 5, 740 $ 1.70 $ 4,610 $ 3,860 $ 0.60 For example, wages and salaries should be $21,000 plus $15.00 per repair-hour. The company expected to work 2,700 repair-hours in May, but actually worked 2,600 repair-hours. The company expects its sales to be $45.00 per repair-hour. Required: Compute the company's activity variances for May.