Question 14.68

14.68 Word-of-mouth communications, continued.

Another variable measured in the experiment described in the previous exercise was the likability of the friend describing her car. Higher values of this score indicate a better opinion. Here is part of the ANOVA table for these data:

Source Degrees of
freedom		 Sum of
squares		 Mean
square
Groups 9.20
Error 0.93
Total 256
  1. Fill in the missing entries in the ANOVA table.
  2. State and for this experiment.
  3. What is the distribution of the statistic under the assumption that is true? Using Table E, give an approximate -value for the ANOVA test. What do you conclude?
  4. What is , the estimate of the within-group variance? What is ?