For Exercises 14.1 and 14.2, see pages 717–718; for 14.3 and 14.4, see page 720; for 14.5 and 14.6, see page 722; for 14.7, see page 724; for 14.8 and 14.9, see page 726; for 14.10 to 14.13, see pages 728–728; for 14.14 and 14.15, see page 731; for 14.16 to 14.19, see page 739; for 14.20 and 14.21, see page 740; for 14.22 and 14.23, see page 741; for 14.24 and 14.25, see page 742; for 14.26 and 14.27, see page 743; for 14.28 and 14.29, see page 744; and for 14.30 and 14.31, see page 748.

Question 14.1

14.1 What’s wrong?

For each of the following, explain what is wrong and why.

  1. ANOVA tests the null hypothesis that the sample means are all equal.
  2. Within-group variation is the variation in the data due to the differences in the sample means.
  3. You use one-way ANOVA to compare the variances of several populations.
  4. A multiple-comparisons procedure is used to compare a relation among means that was specified prior to looking at the data.

14.1

(a) ANOVA does not test the sample means; it should be the population means. (b) This is not within-group variation, it is between-group variation. (c) We are not comparing the variances, we are comparing the means of several populations. (d) This is true for contrasts, not multiplecomparisons. Multiple-comparisons are used when we have no specific relations among means in mind before looking at the data.