5. Calculate the standard score of rst 3 students on a class exam given in the following. The grade system and student marks are given as follows: 5% of the students is going to receive AA, 10% is BA, 16% is BB, 19% is CB, 19% is CC, 16% is DC, 10% is DD and 5% is FF. grades 36I 21I 50, 32, 34, 16, 8, 21, 27, 20, 12, 29, 35, 4D, 77, 28, 26, 24, 65, 25, 18, 26, 89, 64, 69, 40, 9, 70, 11, 13, 46} use standard normal distribution. (hint: standard deviation:21.25] \f