Exercise 3 Albert collects two samples of exam scores for the same midterm: students who are are reading the textbook (Group 1), and students who are not reading the textbook (Group 2), and notices that exams scores seem lower in group 2. Test whether this difference is significant or not. Here are some summary statistics: Group 1: n1 = 30, x = 92.2. sx = 2.5, Group 2: n2 = 20, y = 83.1. sy = 4.0 a) (1.5 points) Perform the appropriate test to determine if this difference is significant at o = 0.05, using Welch's formula for degrees of freedom. Please show all work. Identify your test statistic, calculate its value and distribution under Ho (show your work for the df calculation), p-value, and decision. b) (1 point) Perform a similar appropriate test at o = 0.05, but now assume that there is equal variance between the two groups (use pooled variance) c) (0.5 points) How many degrees of freedom would there be if we used the conservative method instead of Welch's t? Would you expect the p-value to be larger or smaller than using Welch's