A study of the amount of time it takes a mechanic to rebuild…

A study of the amount of time it takes a mechanic to rebuild the transmission for a 2005 Chevrolet Cavalier shows that the mean is 8.4 hours and the standard deviation is 1.8 hours. If 40 mechanics are randomly selected, find the probability that their mean rebuild time exceeds 8.7 hours. a) (1pt) Define x-bar:  b) (1pt) Explain why  x-bar is normal c)  (3pts) Find the probability that their mean rebuild time exceeds 8.7 hours. Round the answer to 3 decimal places.

a) (2pts)  Find the area/probability under the standard norm…

a) (2pts)  Find the area/probability under the standard normal curve to the right of z = -1.25. Round the answer to 3 decimal places. b) (2pts) Find the z-score for which the area under the standard normal curve to its right is 0.70. Round the answer to 2 decimal places.