Green versus yellow. Using the Minitab output in Figure 29.4, verify the values for the sample contrast
2 and its standard error given in Example 29.7. Give a 95% confidence interval for the population contrast L2. Carry out a test of the hypothesis H0: L2= 0 against the two-sided alternative. Be sure to state your conclusions in the setting of the study.
Example 29.7:
Figure 29.4 displays the Minitab ANOVA output for the study on attracting cereal leaf beetles. The pooled estimate of σ is sp = 5.672, and the number of degrees of freedom for error is 20. Minitab does not offer contrasts, so we must use a calculator. The three sample contrasts and their standard errors are
![](https://test.transtutors.com/qimg/7da6b457-f66d-4b9e-a560-86e55a9b8bde.png)
FIGURE 29.4:
![](https://test.transtutors.com/qimg/2f980090-07bd-4eb1-bd7d-d502bc672495.png)