EXAMPLE 14.8 Are the Differences Significant?

CASE 14.1 The ANOVA results produced by JMP are shown in Figure 14.8. The pooled standard deviation is reported as 19.28. The calculated value of the statistic appears under the heading “F Ratio,” and its -value is under the heading “.” The value of is 9.927, with a -value of 0.0001. That is, an of 9.927 or larger would occur by chance one time in 10,000 when the population means are equal. We can reject the null hypothesis that the three populations have equal means for any common choice of significance level. There is very strong evidence that the three populations of consumers do not all have the same mean score.

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