16-27 VARIANCE ANALYSIS, SALES-MIX, AND SALES- QUANTITY VARIANCES. Blank Slate Inc. (BSI) produces tablet computers. BSI markets three different handheld models. Slate Pro is a souped-up version for the executive on the go; Slate is a consumer-oriented version; and SlateLite is a stripped down version for the young adult market. You are BSI's senior vice- president of marketing. The CEO has discovered that the total contribution margin came in lower than budgeted, and it is your responsibility to explain to him why results are different from the budget. Budgeted and actual operating data for the company's third quarter of 2018 are as follows: