In: Statistics and Probability
1.6) Mention the business implications of performing ANOVA for this particular case study.
| A | B | Volunteer | Relief |
| 1 | 1 | 1 | 2.4 |
| 1 | 1 | 2 | 2.7 |
| 1 | 1 | 3 | 2.3 |
| 1 | 1 | 4 | 2.5 |
| 1 | 2 | 1 | 4.6 |
| 1 | 2 | 2 | 4.2 |
| 1 | 2 | 3 | 4.9 |
| 1 | 2 | 4 | 4.7 |
| 1 | 3 | 1 | 4.8 |
| 1 | 3 | 2 | 4.5 |
| 1 | 3 | 3 | 4.4 |
| 1 | 3 | 4 | 4.6 |
| 2 | 1 | 1 | 5.8 |
| 2 | 1 | 2 | 5.2 |
| 2 | 1 | 3 | 5.5 |
| 2 | 1 | 4 | 5.3 |
| 2 | 2 | 1 | 8.9 |
| 2 | 2 | 2 | 9.1 |
| 2 | 2 | 3 | 8.7 |
| 2 | 2 | 4 | 9 |
| 2 | 3 | 1 | 9.1 |
| 2 | 3 | 2 | 9.3 |
| 2 | 3 | 3 | 8.7 |
| 2 | 3 | 4 | 9.4 |
| 3 | 1 | 1 | 6.1 |
| 3 | 1 | 2 | 5.7 |
| 3 | 1 | 3 | 5.9 |
| 3 | 1 | 4 | 6.2 |
| 3 | 2 | 1 | 9.9 |
| 3 | 2 | 2 | 10.5 |
| 3 | 2 | 3 | 10.6 |
| 3 | 2 | 4 | 10.1 |
| 3 | 3 | 1 | 13.5 |
| 3 | 3 | 2 | 13 |
| 3 | 3 | 3 | 13.3 |
| 3 | 3 | 4 | 13.2 |
1.6)
Perform in Minitab software:
Factorial Fit: Relief versus A, B, Volunteer
Estimated Effects and Coefficients for Relief:
| Term | Effect | Coef SE | Coef | t | P |
| Constant | 7.18333 | 0.1477 | 48.63 | 0.000 | |
| A | 5.95000 | 2.97500 | 0.1809 | 16.44 | 0.000 |
| B | 4.35000 | 2.17500 | 0.1809 | 12.02 | 0.000 |
| Volunteer | -0.00667 | -0.00333 | 0.1982 | -0.02 | 0.987 |
| A*B | 2.58750 | 1.29375 | 0.2216 | 5.84 | 0.000 |
| A*Volunteer | 0.02000 | 0.01000 | 0.2427 | 0.04 | 0.967 |
| B*Volunteer | -0.01000 | -0.00500 | 0.2427 | -0.02 | 0.984 |
| A*B*Volunteer | -0.03750 | -0.011875 | 0.2973 | -0.06 | 0.950 |
S = 0.886292; PRESS = 34.4507; R-Sq = 94.13%; R-Sq(pred) = 90.81%; R-Sq(adj) = 92.66%
Analysis of Variance for Relief:
| Source | DF | Seq SS | Adj SS | Adj MS | F | P |
| Main Effects | 3 | 325.950 | 325.950 | 108.650 | 138.32 | 0.000 |
| A | 1 | 212.415 | 212.415 | 212.415 | 270.42 | 0.000 |
| B | 1 | 113.535 | 113.535 | 113.535 | 144.54 | 0.000 |
| Volunteer | 1 | 0.000 | 0.000 | 0.000 | 0.000 | 0.987 |
| 2-Way Interactions | 3 | 26.782 | 26.782 | 8.927 | 11.37 | 0.000 |
| A*B | 1 | 26.781 | 26.781 | 26.781 | 34.09 | 0.000 |
| A*Volenteer | 1 | 0.001 | 0.001 | 0.001 | 0.00 | 0.967 |
| B*Volenteer | 1 | 0.000 | 0.000 | 0.000 | 0.00 | 0.984 |
| 3-Way Interactions | 1 | 0.003 | 0.003 | 0.003 | 0.00 | 0.950 |
| A*B*Volunteer | 1 | 0.003 | 0.003 | 0.003 | 0.00 | 0.950 |
| Residual Error | 28 | 21.994 | 21.994 | 0.786 | ||
| Total | 35 | 374.730 |
Unusual Observations for Relief:
| Obs | StdOrder | Relief | Fit | SE Fit | Residual | St Resid |
| 17 | 17 | 8.9 | 7.1867 | 0.2472 | 1.7133 | 2.01R |
| 18 | 18 | 9.1 | 7.1844 | 0.1618 | 1.9156 | 2.20R |
| 20 | 20 | 9.0 | 7.1800 | 0.2472 | 1.8200 | 2.14R |
R denotes an observation with a large standardized residual.
Estimated Coefficients for Relief using data in uncoded units
| Term | Coef |
| Constant | 2.20556 |
| A | 0.30833 |
| B | -0.46667 |
| Volunteer | -0.058889 |
| A*B | 1.32500 |
| A*Volunteer | 0.031667 |
| B*Volunteer | 0.021667 |
| A*B*Volunteer | -0.012500 |
Residual Plots for Relief:
