Contribution Margin AnalysisSales Blueberry, Inc., sells computer equipment. Management decided early in the year to reduce the price of the speakers in order to increase sales volume. As a result, for the year ended December 31, 2015, the sales increased by $14,700 from the planned level of $744,800. The following information is available from the accounting records for the year ended December 31, 2015: Actual Planned Increase or (Decrease) Sales $759,500 $744,800 $14,700 Number of units sold 21,700 19,600 2,100 Sales price $35 $38 $(3) Variable cost per unit $6 $6 $0