Two versions of a new simplified tax form, Al and A2, need to be evaluated with respect to the time, in hours, it takes to complete the form. Forty persons were selected to fill out Form Al and 40 were selected to fill out Form A2. The summary statistics are:

(a) Find a 95% confidence interval for the difference in means.
(b) If only 80 persons are available for this study, how would you choose the 40 to use form Al?

Transcribed Image Text:

Form Al: -12.2, si # 1.1 Form A2: ỹ 7.2, s2 3.4