a) Following are the marks obtained by 20 pupils of a class. Present the marks in frequency table and find the mean marks. 50, 90 70, 80, 50 40, 60, 40, 80, 50, 70, 70, 80 60, 40 70, 50, 70, 60, 70,

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.