Olivet Devices sells two models of fitness devices. The budgeted price per unit for the wireless model is $52 and the budgeted price per unit for the wireless and cellular model is $97. The master budget called for sales of 51,200 wireless models and 12,800 wireless and cellular models during the current year. Actual results showed sales of 38,000 wireless models, with a price of $49 per unit, and 16,200 wireless and cellular models, with a price of $94 per unit. The standard variable cost per unit is $39 for a wireless model and $74 for a wireless and cellular model. Required: a. Compute the sales activity variance for these data. b. Break down the sales activity variance into mix and quantity parts. Complete this question by entering your answers in the tabs below. Break down the sales activity variance into mix and quantity parts. (Do not round intermediate calculations. Indicate the effect of each variance by selecting "F" for favorable, or "U" for unfavorable. If there is no effect, do not select either option.)