33. Table 10.18 shows the mean number of children in Canadian families, classified by whether the family was English speaking or French speaking and by whether the family was in Quebec or in another province. Let = number of children in family. X = primary language of family, and X = province (Quebec, others).

a) Describe the association between Y and X1, based on the overall means in this table.

b) Describe the association between Y and X, controlling for X2.

c) Explain how it is possible that for each level of province the mean is higher for French speaking families, yet overall the mean is higher for English speaking families (This il- lustrates Simpson's paradox; see Problem 10.8d) TABLE 10.18 Province English French Quebec Other Overall 1.95 164 1.80 1.97 214 1.85