Marginal and absoprtion costing

22.17 AD Ltd manufactures and sells a single product, E, and uses a standard absorption costing system. Standard cost and selling price details for product E are as follows. $ per unit Variable cost 8 Fixed cost. 2 Standard profit 10 Standard selling price 5 The sales volume variance reported for last period was $9,000 adverse. AD Ltd is considering using standard marginal costing as the basis for variance reporting in future. What would be the correct sales volume variance to be shown in a marginal costing operating statement for last period? A $6,428(A) B $6,428 (F) C $12,600 (F) D $12,600 (A) Sir I don't understand how to do this question I understand in marginal costing that fixed cost is not supposed to be there so Standard Margin would be higher hence leading to a less adverse sales variance But the problem I have is by how much would this variance reduce? The fixed cost per unit is $2 But by how much should we multiply this by