Account analysis, high-low. Luwak Coffees wants to find an equation to estimate monthly utility costs. Luwak has been in business for one year and has collected the following cost data for utilities: Month January February March April May June July August September October November December Electricity Bill $ 720 $ 840 $1,098 $ 810 $1,176 $1,248 $1,044 $1,194 $1,260 $1,230 $1,188 $1,266 Kilowatt Hours Used 2,400 2,800 3,660 2,700 3,920 4,160 3,480 3,980 4,200 4,100 3,960 4,220 Telephone Bill $184.
1. Which of the preceding costs is variable? Fixed? Mixed? Explain.
2. Using the high-low method, determine the cost function for each cost.
3. Combine the preceding information to get a monthly operating cost function for the Stein Corporation.
4. Next month, Stein expects to use 400 machine hours, have 80 employees, and ship 9,000 units. Estimate the total operating cost for the month.

Question Completion:

See attached.

Luwak Coffees

1. Water bill is fixed.  Electricity bill is variable.  Telephone bill is mixed.

2. High-Low method:

Water bill = $120 + 0q

Electricity bill = $0.3q

Telephone bill = $140 + $0.02q

where q = the quantity of each cost consumed.

3. Water bill = $120 + 0q

Electricity bill = $0.3q

Telephone bill = $140 + $0.02q

= $260 + $0.32q

4. No solution.  There is no relationship with machine hours, employees, and units with utility bills.

Explanation:

a) Data and Calculations:

Month           Electricity Bill    Kilowatt Hours Used

January            $ 720                       2,400        

February          $ 840                       2,800

March             $1,098                       3,660

April                  $ 810                       2,700

May                 $1,176                       3,920

June               $1,248                       4,160

July                $1,044                       3,480

August           $1,194                       3,980

September   $1,260                       4,200

October        $1,230                       4,100

November    $1,188                        3,960

December  $1,266                        4,220

Telephone Bill $184.

Low cost = Jan  $ 720                2,400

High cost = December  $1,266         4,220

High cost = December  $1,266         4,220

Low cost = Jan                $ 720         2,400

Difference =                     $546         1,820

Variable cost per unit = $546/1,820 = $0.3 per kwh

Fixed cost, using December's figures:

Variable cost = $1,266

Fixed cost = $0 ($1,266 - 4,220 * $0.3)

Telephone bill:

High, June $197.60     2,880

Low, April     178.20      1,960

Difference $18.40        920

Variable cost = $18.40/920 = $0.02

Fixed cost = Total cost - Variable cost

= $197.60 - (2,880 * $0.02)

= $140