Question

Regression Analysis: Rating versus Shelf position

Method

Categorical predictor coding (1, 0)

Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
Regression 2 1511 755.6 5.50 0.013
Shelf position 2 1511 755.6 5.50 0.013
Error 20 2748 137.4
Total 22 4259

Model Summary

S R-sq R-sq(adj) R-sq(pred)
11.7222 35.48% 29.03% 21.34%

Coefficients

Term Coef SE Coef T-Value P-Value VIF
Constant 32.85 4.43 7.41 0.000
Shelf position
bottom 7.40 7.35 1.01 0.326 1.30
top 18.15 5.58 3.26 0.004 1.30

Regression Equation

Rating = 32.85 + 7.40 Shelf position_bottom + 0.0 Shelf position_middle
+ 18.15 Shelf position_top

Using the results from the coefficients table from Minitab, which shelf’s rating is significantly

different from the middle shelf? Explain your decision, including test statistic and p-value

Answer 1