(Step-by-Step) The district manager of Jason’s, a large discount electronics chain, is investigating why certain stores in her region are performing better than
Question: The district manager of Jason’s, a large discount electronics chain, is investigating why certain stores in her region are performing better than others. She believes that three factors are related to total sales: the number of competitors in the region, the population in the surrounding area, and the 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
Predictor Coef StDev t-ratio
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 2.50
- What are the estimated sales for the Bryne store, which has four competitors, a regional population of 0.4 (400,000), and advertising expense of 30 ($30,000)?
- Compute the R2 value.
- Compute the multiple standard error of estimate.
- Conduct a global test of hypothesis to determine whether any of the regression coefficients are not equal to zero. Use the .05 level of significance.
- Conduct tests of hypotheses to determine which of the independent variables have significant regression coefficients. Which variables would you consider eliminating?
Use the .05 significance level.
Deliverable: Word Document 