95% confidence interval, test the null hypothesis. No excel. Show formulas.

1. For the period 1992 to 2001, league expansion caused major league baseball rosters to increase 15%. However, the number of players being put on the disabled list due to injury increased 32% over the same period (USA Today, July 8, 2002). A research question addressed whether major league players being put on the disabled list are on the list longer in 2001 than players put on the disabled list a decade earlier. The statistics for the two years are as follows: 2001 Season 1992 Season Sample Players n1 = 45 n2 = 38 Avg. # of days X1 = 60 X2 = 51 Standard deviation S, = 18 S2 = 15 Assume that o? = 02. (a) [3 points] Establish a 95% confidence interval to estimate the difference in the number of injury days between the 2001 and 1992 seasons. (b) [3 points] Test the null hypothesis Ho: M1 - M2 5 0 against the alternative hypothesis Ha: M1 - M2 > 0. Test this at the 10%, 5%, and 1% level of significance. What do you conclude