The following data are available for the most recent year of operations for Slacker & Sons. The revenue portion of the sales activity variance is $336,000F Master budget based on actual sales of 167,000 units: Revenue Materials Labor Variable manufacturing overhead and administrative costs Fixed manufacturing overhead and administrative costs $4,200,000 867,000 642,000 142,000 470,000 Required a. How many units were actually sold in the most recent period? (Do not round intermediate calculations.) I sales 167,000 units 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.) SLACKER &SONS Sales Activity Variance Flexible Budget S 4,536,000 Sales Activity Variance Master Budget Sales revenue S 4,200,000 Variable costs Materials Direct labor Variable manufacturing and administrative 867,000 642.000 142.000 S 1,651,000 S 2,549,000 Total variable costs Contribution margin Fixed costs S 4,536,000 Manufacturing overhead and administrative Total fixed costs Operating profits 470,000 S 470,000 S 470,000 S 470,000 S 2,079,000 S 4,066,000