A new study has found that, on average, 6- to 12-year-old children are spending less time on household chores today compared to 1981 levels (The Wall Street Journal, August 27, 2008). Suppose two samples representative of the study's results report the following summary statistics for the two periods: PG-69

a. Specify th e co m p etin g hyp otheses to test th e study's claim that children today spend less tim e on household chores as com pared to children in 1981.

b. Calculate t h e v a lu e o f t h e te s t statistic a s s u m i n g th a t th e unknown population variances are equal.

c. Approximate the p -value.

d. At the 5% significance level, do the data support the study's claim? Explain.

e. Repeat the hypothesis test using the critical value approach.

1981 Levels X 30 minutes = S =4.2 minutes n-30 2008 Levels x2 = 24 minutes 5 = 3.9 minutes n = 30