McConaughy (1980) has argued that younger children organize stories in terms of simple descriptive (“and then . . .”) models, whereas older children incorporate causal statements and social inferences. Suppose we asked two groups of children differing in age to summarize a story they just read. We then counted the number of statements in the summary that can be classed as inferences. The data are shown.

Younger Older Children Children 0 4 1 7 0 6 3 4 2 8 5 7 2 5

(a) Analyze these data using the two-tailed rank-sum test.

(b) What would you conclude?