A normal population has mean it : 63 and standard deviation 5 :16. (a) What proportion of the population is greater than 100? (b) What is the probability that a randomly chosen value will be less than 80? Round the answers to four decimal places. Part: 0 / 2 Part 1 of2 The proportion of the population greater than 100 is l l. Fish story: According to a report by the U.S. Fish and Wildlife Service, the mean length of six-year-old rainbow trout in the Arolik River in Alaska is 478 millimeters with a standard deviation of 38 millimeters. Assume these lengths are normally distributed. (a) What proportion of six-year-old rainbow trout are less than 442 millimeters long? (b) What proportion of sixyearold rainbow trout are between 400 and 500 millimeters long? (:2) Is it unusual for a sixyearold rainbow trout to be less than 372 millimeters long? Round the answers to at least four decimal places. Part: 0/3 How much do you study? A survey among freshmen at a certain university revealed that the number of hours spent studying the week before final exams was normally distributed with mean 28 and standard deviation 6. Use the TI-84 PLUS calculator to answer the following. Round the answer to at least four decimal places. (a) What proportion of students studied more than 37 hours? (b) What is the probability that a randomly selected student spent between 14 and 33 hours studying? (c) What proportion of students studied less than 33 hours? Part: 0/3