A researcher investigated four different word lists for use in hearing assessments. She wanted to know whether the lists were equally difcult to understand in the presence of a noisy background. To nd out, she tested 96 subjects with normal hearing. She randomly assigned 24 to each of the four word lists and measured the number of words perceived correctly in the presence of background noise. Here are the summary statistics for number of words perceived correctly for each of the four words lists. Word List A Word List B Word List C Word list D Sample size 24 24 24 24 Sample mean 32.5 34.0 25.75 26.25 S "3'"? Standard 5.1 11 5.3 6.7 deVIatIon Below are the p-values for each of the pairwise comparisons Comparison p-values Word List A versus Word List B 0.41 Word List A versus Word List C 0.0004 Word List A versus Word List D 0.0009 Word List B versus Word List C 0.00002 Word List B versus Word List D 0.00005 Word List C versus Word List D 0.79 One of the conditions for using the Analysis of Variance condition is that the spread of the data is the same for all comparison groups. Is it safe to say that GA = 03 = oc = GD? 0 No, since all of the sample standard deviations are different. C) No, since the difference between the largest and smallest sample standard deviations is 2. It must be less than 2 for us to feel comfortable saying that the four population standard deviations are the same. 0 Yes, since the ratio of the largest to smallest sample standard deviations is 11 I 5.1 = 1.39