From the formulas in Table 17.4, calculate SST- (n- 1)s 2 - 19 x 4799.358 = 91,187.805; SSM = 5[(291.4- 314.9) 2 + (323.2- 314.9) 2 +

(274.8 - 314.9) 2 + (371.2 - 314.9) 2 = 27,234.20; and SSE - SST - SSM

= 91,187.80 - 27,234.20 = 63,953.60. Table 17.10 gives the ANOVA table.

From Table V, the critical F3,16df -- 3.24. The calculated F - 2.27 is smaller, so H0 is not rejected; mean parasite infestation is not shown to differ from batch to batch. (With a nonsignificant F, we are not concerned that a subordinate pair will be significant; thus, we do not pursue a multiple comparisons procedure.) From a statistical software package, the calculated p = 0.120.