TABLE 11-7
An agronomist wants to compare the crop yield of 3 varieties of chickpea seeds. She plants 15 fields, 5 with each variety. She then measures the crop yield in bushels per acre. Treating this as a completely randomized design, the results are presented in the table that follows.
$$\begin{array} { c r r r }
\text { Trial } & \text { Smith } & \text { Walsh } & \text { Trevor } \
\hline 1 & 11.1 & 19.0 & 14.6 \
2 & 13.5 & 18.0 & 15.7 \
3 & 15.3 & 19.8 & 16.8 \
4 & 14.6 & 19.6 & 16.7 \
5 & 9.8 & 16.6 & 15.2
\end{array}$$
-Referring to Table 11-7, the test is valid only if the population of crop yields has the same variance for the 3 varieties.

Question

TABLE 11-7 
An agronomist wants to compare the crop yield of 3 varieties of chickpea seeds. She plants 15 fields, 5 with each variety. She then measures the crop yield in bushels per acre. Treating this as a completely randomized design, the results are presented in the table that follows.
 $$\begin{array} { c r r r } 
\text { Trial } & \text { Smith } & \text { Walsh } & \text { Trevor } \
\hline 1 & 11.1 & 19.0 & 14.6 \
2 & 13.5 & 18.0 & 15.7 \
3 & 15.3 & 19.8 & 16.8 \
4 & 14.6 & 19.6 & 16.7 \
5 & 9.8 & 16.6 & 15.2
\end{array}$$
-Referring to Table 11-7, the test is valid only if the population of crop yields has the same variance for the 3 varieties.

Quizplus · Accepted Answer

The assumption of equal variances (homogeneity of variance) is necessary for the validity of ANOVA, which is likely the test being referred to for comparing the means of the three groups.

TABLE 11-7 an Agronomist Wants to Compare the Crop

TABLE 11-7
an Agronomist Wants to Compare the Crop