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.)