The following data are available for the most recent year of operations for Slacker & Sons. The revenue portion of the sales activity variance is $225,000 F. Master budget based on actual sales of 170,000 units: Revenue $ 4,500,000 Materials 870,000 Labor 645,000 Variable manufacturing overhead and administrative costs 145,000 Fixed manufacturing overhead and administrative costs 500,000 Required: a. How many units were actually sold in the most recent period? (Do not round intermediate calculations.) b. Prepare a sales activity variance for the most recent year for Slacker & Sons. (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.)