Interpreting the multiple regression analysis for the given MINITAB output
The district manager of Jasons, a large discount electronics chain, is investigating why certain stores in her region are performing better than others. She believes that 3 factors are related to total sales: the number of competitors in the region, the population in the surrounding area, and amount spent on advertising. From her district, consisting of several hundred stores, she selects a random sample of 30 stores. For each store she gathered the following information.
Y =

total sales last year (in $ thousands).

X_{1} =

number of competitors in the region.

X_{2} =

population of the region (in millions).

X_{3} =

advertising expense (in $ thousands).

The sample data were run on MINITAB, with the following results.
Analysis of variance

SOURCE

DF

SS

MS

Regression

3

3050.00

1016.67

Error

26

2200.00

84.62

Total

29

5250.00

Â

Predictor

Coef

StDev

tratio

Constant

14.00

7.00

2.00

X 1

1.00

0.70

1.43

X 2

30.00

5.20

5.77

X 3

0.20

0.08


a) What are the estimated sales for the Bryne store, which has 4 competitors, a regional population of 0.4 (400,000), and advertising expense of 30 ($30,000)?
b) find out the R_{2} value.
c) find out the multiple standard error of estimate.