Variances

Hi John sir, plz help me with the following question, The answer i find is quiet different and m confused. A company operates std absorption costing system. The following information has been extracted from the standard cost card of one of its products: Budgeted production 1,500 units Direct materials cost: 7 kgs * $4.10 = $28.70 per unit Actual results for the period were as follows: Production 1600 units Direct material ( purchased and used ) 1200 kgs, cost $52,200 It has subsequently been noted that, due to a change in economic conditions, the best price that the material could have been purchased for was $4.50 per kg during the period. Find material price planning variance I could not understand the solution , it takes 0.4 difference in price and multiplies it with 11200 units. 11200 UNITS are confusing me.