The standard costs and actual costs for factory overhead for the manufacture of 2,700 units of actual production are as follows:

Standard Costs

Fixed overhead (based on 10,000 hours)3 hours per unit @ $0.72 per hourVariable overhead3 hours per unit @ $2.01 per hour

Actual Costs

Total variable cost, $18,100Total fixed cost, $8,100

The amount of the total factory overhead cost variance is

a.$3,187 favorable

b.$3,187 unfavorable

c.$1,819 unfavorable

d.$4,555 favorable