Variance Analysis

Hi John, Can you help with this one... A company uses a standard absorption costing system. The following details have been extracted from its budget for April. Fixed production overhead cost $48,000 Production (units) 4,800 In April the fixed production overhead cost was under absorbed by $8,000 and the fixed production overhead expenditure variance was $2,000 adverse. What was the actual number of units produced? The correct answer is: 4,200 Actual expenditure = $(48,000 + 2,000) = $50,000 Overhead absorbed = $(50,000 – 8,000) = $42,000 Overhead absorption rate per unit = $48,000 / 4,800 = $10 Number of units produced = $42,000 / $10 = 4,200 I'm a bit fuzzy on the logic of subtracting the 8000 from the 50000 to get the overhead absorbed...