8. Lots of people claim that having a pet helps lower their stress level. Use the following summary data to test the claim that there is a lower average stress level among pet owners (group 1) than among non-owners (group 2) at the .05 level of significance. X1 = 16.25, X2 = 20.95, s1 = 4.00, s2 = 5.10, n1 = 29, n2 = 25