A MA336 Spring 2022 Practice TES X + C a webassign.net/web/Student/Assignment-Responses/last?dep=29081386 M Gmail YouTube . Maps |Living Environment.. Suppose that the distribution of scores on an exam can be described by a normal curve with mean 140. The 16th percentile of this distribution is 100. (Use the Empirical Rule.) (a) What is the 84th percentile? (b) What is the approximate value of the standard deviation of exam scores? (c) What z score is associated with an exam score of 160? (d) What percentile corresponds to an exam score of 220? O 0.15 0 0.3 O 2.5 O 13.5 O 34 O 50 O 68 O 86.5 O 97.5 O 99.7 O 99.85 (e) Do you think there were many scores below 20? Explain. A score of 20 is standard deviations below the mean, and so the percentage of scores below 20 would be approximately -Select