Jake's Roof Repair has provided the following data concerning its costs: For example, wages and salaries should be $20,600 plus $15.00 per repair-hour. The company expected to work 2,700 repair-hours May, but actually worked 2,600 repair-hours. The company expects its sales to be $54,00 per repalr-hour: Required: Compute the company's activity variances for May. (Indicate the effect of each variance by selecting "F" for favorable, " U " for unfavorable, and "None" for no effect (i.e., zero variance), Input all amounts as positive values.)