In: Accounting
Will Pugh, director of cost operations for MicroPak, wishes to develop an accurate cost function to explain and predict support costs in the company’s printed circuit board assembly operation. Mr. Pugh is concerned that the cost function he currently uses – based on direct labor costs – is not accurate enough for proper planning and control of support costs. Mr. Pugh directed one of his financial analysts to obtain a random sample of 25 weeks of support costs and three possible cost drivers in the circuit-board assembly department: direct labor hours, number of boards assembled and average cycle time of boards assembled. (Average cycle time is the average time between start and certified completion – after quality testing – of boards assembled during a week.) Mr. Pugh wants his analyst to use regression analysis to demonstrate which cost driver best explains support costs.
Week |
Assembly Support costs (Y) |
Direct Labor Hours (X1) |
Number of completed boards (X2) |
Average Cycle Time (Hours) (X3) |
|
1 |
$66,402 |
7,619 |
2,983 |
186.44 |
|
2 |
$56,943 |
7,678 |
2,830 |
139.14 |
|
3 |
$50,337 |
7,816 |
2,413 |
151.13 |
|
4 |
$50,096 |
7,659 |
2,221 |
138.30 |
|
5 |
$64,241 |
7,646 |
2,701 |
158.63 |
|
6 |
$60,846 |
7,765 |
2,656 |
148.71 |
|
7 |
$43,119 |
7,685 |
2,495 |
105.85 |
|
8 |
$63,412 |
7,962 |
2,128 |
174.02 |
|
9 |
$59,283 |
7,793 |
2,127 |
155.30 |
|
10 |
$60,070 |
7,732 |
2,127 |
162.20 |
|
11 |
$53,345 |
7,771 |
2,338 |
142.97 |
|
12 |
$65,027 |
7,842 |
2,685 |
176.08 |
|
13 |
$58,220 |
7,940 |
2,602 |
150.19 |
|
14 |
$65,406 |
7,750 |
2,029 |
194.06 |
|
15 |
$35,268 |
7,954 |
2,136 |
100.51 |
|
16 |
$46,394 |
7,768 |
2,046 |
137.47 |
|
17 |
$71,877 |
7,764 |
2,786 |
197.44 |
|
18 |
$61,903 |
7,635 |
2,822 |
164.69 |
|
19 |
$50,009 |
7,849 |
2,178 |
141.95 |
|
20 |
$49,327 |
7,869 |
2,244 |
123.37 |
|
21 |
$44,703 |
7,576 |
2,195 |
128.25 |
|
22 |
$45,582 |
7,557 |
2,370 |
106.16 |
|
23 |
$43,818 |
7,569 |
2,016 |
131.41 |
|
24 |
$62,122 |
7,672 |
2,515 |
154.88 |
|
25 |
$52,403 |
7,653 |
2,942 |
140.07 |
Instructions: The questions that follow pertain to the above data set. Enter your responses in the spaces where indicated. This problem will require the use of MS Excel and/or StatPlus to estimate regression models.
Required:
Use regression analysis to estimate separate cost
functions for each of the three potential cost drivers (i.e.,
estimate the regressions separately for X1, X2 and X3, rather than
a single regression that includes all three variables) and then
respond to the questions below. Make sure that you properly
identify your "Y" and "X" variables in your regression
program.
In addition to the discussion questions, you will attach
your worksheet that includes your output for each of the three
regressions.
A) Based on your regression results, enter the cost
functions (using good form) for each of the three cost
drivers.
B) Based on your analyses of the regression results, which is the
best cost driver for support costs? Why?
C) What is the economic interpretation of the best cost
function?
Instruction to
create regression model in MS Excel
1. On the Data tab, in the Analysis group, click Data
Analysis.
2. Select Regression and click OK.
3. Select the Assembly Support costs (Y) Range . This is the
dependent variable
4. Select the X1 / X2 / X3 Range. These are the independent
variables.
5. Check Labels ( If you have selected label headings also in step
3 & Step 4)
6. Click OK.
Result
Analysis