A New Study Has Found That,on Average,6- to 12-Year-Old Children

Multiple Choice

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.Suppose two samples representative of the study's results report the following summary statistics for the two periods. Which of the following is the correct value of the test statistic assuming that the unknown population variances are equal?

A) z = -5.73
B) t₅₈ = 5.73
C) z = 5.73
D) t₅₉ = -5.73