Hi, I need help solving this problem. I don't understand how to find probability.

a. If a pilot is randomly selected, nd the probability that his weight is between 120 lb and 171 lb. The probability is approximately . (Round to four decimal places as needed.) b. If 34 different pilots are randomly selected, nd the probability that their mean weight is between 120 lb and 171 lb. The probability is approximately . (Round to four decimal places as needed.) c. When redesigning the ejection seat, which probability is more relevant? Part (b) because the seat performance for a single pilot is more important Part (a) because the seat performance for a single pilot is more important. Part (b) because the seat performance for a sample of pilots is more important. 9.0!\"? Part (a) because the seat performance for a sample of pilots is more important. An engineer is going to redesign an ejection seat for an airplane. The seat was designed for pilots weighing between 120 lb and 171 lb. The new population of pilots has normally distributed weights with a mean of 127 lb and a standard deviation of 34.5 lb