7. [ Maximum points: 141 The following values represent the test scores of 31 students in a mathematics test. 45 40 67 72 68 70 91 85 76 55 62 63 45 32 65 87 72 54 60 61 72: 63 97 75 54 66: 68 45 67 83 63 (a) Determine the mean and standard deviation of the scores. 131 (b) The teacher suggests the scores are approximately normally distributed. By [11] considering at least three intervals analyse the scores and comment on the teachers claim