An investigation is conducted to determine if the mean age of welfare recipients differs between two cities A and B. Random samples of 75 and 100 welfare recipients are selected from city A and city B, respectively, and the following computations are made.

(a) Do the data provide strong evidence that the mean ages are different in city A and city B? (Test at α = .02.)
(b) Construct a 98% confidence interval for the difference in mean ages between A and B.
(c) Construct a 98% confidence interval for the mean age for city A and city B individually.

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City A City B Mean Standard deviation 6.8 43.2 7.5 37.8