A (b) Let U ={1,2, 3, ..., 9}be a universal set, and let A == {1, 2, 3, 4, 5} and B = {4, 5, 6, 7}.
Find the following:
(i) the compliment A of A,
(i) the set difference B-A,
(iii)the symmetric difference AOB.

3.17 scores on stats final. below are final exam scores of 20 introductory statistics students. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 57, 66, 69, 71, 72, 73, 74, 77, 78, 78, 79, 79, 81, 81, 82, 83, 83, 88, 89, 94 (a) the mean score is 77.7 points. with a standard deviation of 8.44 points. use this information to determine if the scores approximately follow the 68-95-99.7% rule. (b) do these data appear to follow a normal distribution? explain your reasoning using the graphs provided below.