1. The delivery trucks of Slavin Transport Company incurred $3,600 of maintenance costs during
the busiest month of 2004, in which 12,000 miles were driven collectively. During the slowest
month, $2,800 in maintenance costs were incurred, and 8,000 miles were driven. Using the high-
low method, what maintenance cost would the company expect to incur if 15,000 miles were
driven? A. $3,000 B. $4,400 C. $4,000 D. $4,200
Solution
Remember that the method is to first split the costs into variable and fixed components. To do
that, we need to make this formula:
(C2 - C1) / (V2 - V1) (V=Volume and C = Cost. "!" and "2" are highest and lowest)
SO Variable =
(3600 - 2800) / ($12000 - $8000)
800 / $4,000
or 20 cents a unit.
NEXT we have to calculate the estimated FIXED costs.
Fixed Costs = TOTAL COSTS - Total Variable costs
We can use EITHER hi or low. Lets use High
Fixed = $3600 - (20 cents * 12000 miles)
Fixed = $3600 - $2400
Fixed = $1200
(note that for the LOW volume of miles it also works -
Total costs = $1200 (fixed) + Variable (8000 miles * 25cents)

2. Total costs = $1200 + 2000
Total costs = $3200
NOW we move to solving the answer of costs at 15000 miles:
Total costs = fixed ($1200) + Variable (20 cents * 15000 miles)
Total costs = $1200+ 3000
Total costs = $4200
Answer D ) 4200