Assume that the amounts of weight that male college students gain during their freshman year are normally distributed with a mean of u= 1.4 kg and a standard deviation of u= 5.6 kg. Complete parts (a) through (c) below.

a. If 1 male college student is randomly selected, find the probability that he gains between 0 kg and 3 kg during freshman year. The probability is

b. If 9 male college students are randomly selected, find the probability that their mean weight gain during freshman year is between 0 kg and 3 kg. The probability is

c. Why can the normal distribution be used in part (b), even though the sample size does not exceed 30?