12.5 Joystick types. Example 12.1 (page 645) describes a study designed to compare different joystick types on the time it takes to complete a navigation mission. In Exercise 12.3 (page 653), you described the ANOVA model for this study. The three joystick types are designated 1, 2, and 3. The following table summarizes the time (seconds) data.
| Joystick | s | n | |
|---|---|---|---|
| 1 | 279 | 78 | 20 |
| 2 | 245 | 68 | 20 |
| 3 | 258 | 80 | 20 |
(a) Is it reasonable to pool the standard deviations for these data? Explain your answer.
(b) For each parameter in your model from Exercise 12.3, give the estimate.