For 25 points

Which of the equations is the correct representation of the following word problem?

A student's grades are 92, 73, 87, and 91. What is the average of the student's grades?

(92 + 73 + 87)/3 = x

4(92 + 73 + 87 + 91) = x

(92 + 73 + 87 + 91)/4 = x

(92 + 73 + 87 + 91)/5 = x

An engineer is going to redesign an ejection seat for an airplane. the seat was designed for pilots weighing between 120 lb and 161 lb. the new population of pilots has normally distributed weights with a mean of 125 lb and a standard deviation of 28.1 lb. a)if a pilot is randomly selected, find the probability that his weight is between 120 lb and 161 lb. the probability is approximately? b. if 36 different pilots are randomly selected, find the probability that their mean weight is between 120 lb and 161 lb. the probability is approximately? c. when redesigning the ejection seat, which probability is more relevant? . part (b) because the seat performance for a single pilot is more important. b. part (b) because the seat performance for a sample of pilots is more important. c. part (a) because the seat performance for a sample of pilots is more important. d. part (a) because the seat performance for a single pilot is more important.