res for 15 students in a very large calculus class 81 81 97 81 88 98 62 68 62 67 81 62 82 86 90 What is the mean of this data set? 076.34 74.55 82.49 079.07 What is the mode of this data set? O 88 090 081 062 What is the variance of this data set? 0166.2657 0149.4952 O 139.5289 165.586 What is the standard deviation of this data set? 12.2268 11.8122 O 12.8944 O 12.868 What is the range of this data set? 028