Problem:
1. The following cost graphs illustrate various types of cost behavior:
For each of the following costs, identify the cost graph that best illustrates its cost behavior as the number of units produced increases.
(a) Total direct materials cost
(b) Electricity costs of $2,000 per month plus $0.09 per kilowatt-hour
(c) Per-unit direct labor cost
(d) Salary of quality control supervisor, $10,000 per month
(e) Per-unit cost of straight-line depreciation on factory equipment