Please find the partial multiple regression analysis performed to explore the relation between the sales (in hundreds) and the independent variables price(in dollars), promotional expenditure(in hundreds of dollars) and the quality score ( 0-100) for a very popular Christmas season toy.
The regression equation is
Sales = 343 - 0.234 Price + 2.70 Promotional exp + 0.220 Quality
Predictor Coef SE Coef T P VIF
Constant 343.20 62.59
Price -0.23358 0.05734 2.415
Promotional exp 2.704 1.240 1.047
Quality 0.2204 0.1429 2.387
S = 6.75231 R-Sq = 88.4%
Analysis of Variance
Source DF SS MS F
Regression 3 3477.5 1159.2 25.42
Residual Error 10 455.9 45.6
Total 13 3933.4
Answer questions A - F based on the above analysis
A) Is the factor Quality significant at α=0.05 ? Perform the test of hypothesis. (10 points)
B) Construct a 95% confidence interval estimate of the population slope of sales with price and also state whether price is a significant factor in predicting sales. (10 points)
C) What is the value of the partial F test statistic (FSTAT) for the independent variable 'Promotional Exp' ? (10 points)
D) Is there a problem with multi-collinearity among independent variables in this analysis? Explain. (10 points)
E) What is the adjusted R2 value? (10 points)
F) Based on the ANOVA presented, perform the F- test and state if the regression is significant? (α=0.05)