In: Statistics and Probability
A statistical program is recommended.
A study investigated the relationship between audit delay (Delay), the length of time from a company's fiscal year-end to the date of the auditor's report, and variables that describe the client and the auditor. Some of the independent variables that were included in this study follow.
Industry | A dummy variable coded 1 if the firm was an industrial company or 0 if the firm was a bank, savings and loan, or insurance company. |
---|---|
Public | A dummy variable coded 1 if the company was traded on an organized exchange or over the counter; otherwise coded 0. |
Quality | A measure of overall quality of internal controls, as judged by the auditor, on a five-point scale ranging from "virtually none" (1) to "excellent" (5). |
Finished | A measure ranging from 1 to 4, as judged by the auditor, where 1 indicates "all work performed subsequent to year-end" and 4 indicates "most work performed prior to year-end." |
A sample of 40 companies provided the following data.
Delay | Industry | Public | Quality | Finished |
---|---|---|---|---|
62 | 0 | 0 | 3 | 1 |
45 | 0 | 1 | 3 | 3 |
54 | 0 | 0 | 2 | 2 |
71 | 0 | 1 | 1 | 2 |
91 | 0 | 0 | 1 | 1 |
62 | 0 | 0 | 4 | 4 |
61 | 0 | 0 | 3 | 2 |
69 | 0 | 1 | 5 | 2 |
80 | 0 | 0 | 1 | 1 |
52 | 0 | 0 | 5 | 3 |
47 | 0 | 0 | 3 | 2 |
65 | 0 | 1 | 2 | 3 |
60 | 0 | 0 | 1 | 3 |
81 | 1 | 0 | 1 | 2 |
73 | 1 | 0 | 2 | 2 |
89 | 1 | 0 | 2 | 1 |
71 | 1 | 0 | 5 | 4 |
76 | 1 | 0 | 2 | 2 |
68 | 1 | 0 | 1 | 2 |
68 | 1 | 0 | 5 | 2 |
86 | 1 | 0 | 2 | 2 |
76 | 1 | 1 | 3 | 1 |
67 | 1 | 0 | 2 | 3 |
57 | 1 | 0 | 4 | 2 |
55 | 1 | 1 | 3 | 2 |
54 | 1 | 0 | 5 | 2 |
69 | 1 | 0 | 3 | 3 |
82 | 1 | 0 | 5 | 1 |
94 | 1 | 0 | 1 | 1 |
74 | 1 | 1 | 5 | 2 |
75 | 1 | 1 | 4 | 3 |
69 | 1 | 0 | 2 | 2 |
71 | 1 | 0 | 4 | 4 |
79 | 1 | 0 | 5 | 2 |
80 | 1 | 0 | 1 | 4 |
91 | 1 | 0 | 4 | 1 |
92 | 1 | 0 | 1 | 4 |
46 | 1 | 1 | 4 | 3 |
72 | 1 | 0 | 5 | 2 |
85 | 1 | 0 | 5 | 1 |
(a) Develop the estimated regression equation using all of the independent variables. Use x1 for Industry, x2 for Public, x3 for Quality, and x4 for Finished. (Round your numerical values to two decimal places.)
ŷ =
(c) Develop a scatter diagram showing Delay as a function of Finished.
On the basis of your observations about the relationship between Delay and Finished, use best-subsets regression to develop an alternative estimated regression equation to the one developed in (a) to explain as much of the variability in Delay as possible. Use x1 for Industry, x2 for Public, x3 for Quality, and x4 for Finished. (Round your numerical values to two decimal places.)
ŷ =
(A)
We have the data:
Delay | Industry | Public | Quality | Finished |
62 | 0 | 0 | 3 | 1 |
45 | 0 | 1 | 3 | 3 |
54 | 0 | 0 | 2 | 2 |
71 | 0 | 1 | 1 | 2 |
91 | 0 | 0 | 1 | 1 |
62 | 0 | 0 | 4 | 4 |
61 | 0 | 0 | 3 | 2 |
69 | 0 | 1 | 5 | 2 |
80 | 0 | 0 | 1 | 1 |
52 | 0 | 0 | 5 | 3 |
47 | 0 | 0 | 3 | 2 |
65 | 0 | 1 | 2 | 3 |
60 | 0 | 0 | 1 | 3 |
81 | 1 | 0 | 1 | 2 |
73 | 1 | 0 | 2 | 2 |
89 | 1 | 0 | 2 | 1 |
71 | 1 | 0 | 5 | 4 |
76 | 1 | 0 | 2 | 2 |
68 | 1 | 0 | 1 | 2 |
68 | 1 | 0 | 5 | 2 |
86 | 1 | 0 | 2 | 2 |
76 | 1 | 1 | 3 | 1 |
67 | 1 | 0 | 2 | 3 |
57 | 1 | 0 | 4 | 2 |
55 | 1 | 1 | 3 | 2 |
54 | 1 | 0 | 5 | 2 |
69 | 1 | 0 | 3 | 3 |
82 | 1 | 0 | 5 | 1 |
94 | 1 | 0 | 1 | 1 |
74 | 1 | 1 | 5 | 2 |
75 | 1 | 1 | 4 | 3 |
69 | 1 | 0 | 2 | 2 |
71 | 1 | 0 | 4 | 4 |
79 | 1 | 0 | 5 | 2 |
80 | 1 | 0 | 1 | 4 |
91 | 1 | 0 | 4 | 1 |
92 | 1 | 0 | 1 | 4 |
46 | 1 | 1 | 4 | 3 |
72 | 1 | 0 | 5 | 2 |
85 | 1 | 0 | 5 | 1 |
EXCEL-->DATA-->DATA ANALYSIS-->REGRESSION;
SUMMARY OUTPUT | ||||||||
Regression Statistics | ||||||||
Multiple R | 0.618518551 | |||||||
R Square | 0.382565198 | |||||||
Adjusted R Square | 0.312001221 | |||||||
Standard Error | 10.92351796 | |||||||
Observations | 40 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 4 | 2587.661436 | 646.915359 | 5.421536774 | 0.001665508 | |||
Residual | 35 | 4176.313564 | 119.3232447 | |||||
Total | 39 | 6763.975 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 95.0% | Upper 95.0% | |
Intercept | 80.42857175 | 5.91586135 | 13.59541189 | 1.57309E-15 | 68.41873472 | 92.43840878 | 68.41873472 | 92.43840878 |
X Variable 1 | 11.94418923 | 3.797800763 | 3.145027865 | 0.003379559 | 4.234243788 | 19.65413466 | 4.234243788 | 19.65413466 |
X Variable 2 | -4.816257126 | 4.229181312 | -1.138815475 | 0.262515036 | -13.40195164 | 3.769437385 | -13.40195164 | 3.769437385 |
X Variable 3 | -2.623635035 | 1.183593557 | -2.216668907 | 0.033238643 | -5.026457698 | -0.220812372 | -5.026457698 | -0.220812372 |
X Variable 4 | -4.072510795 | 1.851430781 | -2.199655982 | 0.034527054 | -7.831115103 | -0.313906486 | -7.831115103 | -0.313906486 |
Y=80.42857175+11.94418923 X1 -4816257126 X2- 2.62365035 X3-4.072510795 X4
R2=0.618518551 hence there is 0.618518551 or 61.85% variability in Y due to x1 for Industry, x2 for Public, x3 for Quality, and x4 for Finished
(C)
We have:
1 | 62 |
3 | 45 |
2 | 54 |
2 | 71 |
1 | 91 |
4 | 62 |
2 | 61 |
2 | 69 |
1 | 80 |
3 | 52 |
2 | 47 |
3 | 65 |
3 | 60 |
2 | 81 |
2 | 73 |
1 | 89 |
4 | 71 |
2 | 76 |
2 | 68 |
2 | 68 |
2 | 86 |
1 | 76 |
3 | 67 |
2 | 57 |
2 | 55 |
2 | 54 |
3 | 69 |
1 | 82 |
1 | 94 |
2 | 74 |
3 | 75 |
2 | 69 |
4 | 71 |
2 | 79 |
4 | 80 |
1 | 91 |
4 | 92 |
3 | 46 |
2 | 72 |
1 | 85 |
HENCE, Y=-4.3824X+80.226
this means that for 1 unit increase in FINISHED there is 4.3824 units decrease in delay.
R2=0.0993 hence there is 0.0993 or 9.93% variability in DELAY due to FINISHED.
please rate my answer and comment for doubts.