Mike's Radiator Services specializes in the repair and replacement of radlators for passenger vehicles. Variable and fixed costs related to installation activities for the most recent month (January) are listed below: Item Number of radiators replaced Variable expenses: Direct materials (new radiators) Direct labour (2 hours per installation) Indirect materials Fixed expenses: Installation supervisor's wages Equipment depreciation Insurance and utilities for garage 110 $55,000 5,500 550 $ 9,152 1,144 814 Required: 2. Mike expects that 88 radiators will be installed in February and that this level of activity is within the relevant range for all variable and fixed expenses. a & b-1. Calculate the total expense and per unit amounts for each of the variable and fixed cost items above. (Round "per unit" answers to 2 decimal places.) February (Total Cost) February Per Unit Item Variable expenses: Direct materials (new radiators) $ 44,000.00 %24 500.00 Direct labour (2 hours per installation) $ 8,800.00 S 50.00 Indirect materials $ 440.00 $ 5.00 Fixed expenses: Installation supervisor's wages Equipment depreciation Insurance and utilities for garage b-2. Explain any differences in the per unit amounts between January and February.