Percent of words stuttered was recorded for 9 subjects whose disability had been classified as mild, moderate, or severe.
a. Present the data as a column of quantitative responses (in increasing order) and a column of categorical explanatory values.
b. Recall that group degrees of freedom (in the numerator) are I 1, where I is the number of groups. Error degrees of freedom (in the denominator) are N I, where N is the total number of observations. If ANOVA were to be used to make a comparison, how many degrees of freedom would the F statistic have in the numerator and how many in the denominator?
c. A potential problem with the use of ANOVA for comparing the three groups is that the standard deviation for one of the groups is much larger than the other two. Tell which group it is, just by looking at how different the values are within each of the three groups.