Question 9.2: For the data in Table 9.1, compute SSTr and SSE.

The sample means arc presented in Table 9.1. They are

\bar{X}_{1 .}=253.8 \quad \bar{X}_{2 .}=263.2 \quad \bar{X}_{3 .}=271.0 \quad \bar{X}_{4 .}=262.0

The sample grand mean was computed in Example 9.1 to be \bar{X}_{ \ldots}=262.5. We now use Equation (9.4) to calculate SSTr.

SSTr=\sum\limits_{i=1}^l J_i\left(\bar{X}_i-\bar{X}_{..}\right)^2          (9.4)

To compute SSE we will use Equation (9.9), since the sample standard deviations s_i have already been presented in Table 9.1.

SSE =\sum\limits_{i=1}^l\left(J_i-1\right) s_i^2            (9.9)