The Average Speed of Cars Passing a Checkpoint Is 60

Multiple Choice

The average speed of cars passing a checkpoint is 60 miles per hour with a standard deviation of 8 miles per hour.Fifty (50) passing cars are clocked at random from this checkpoint.The probability that the sample mean will be between 57 and 62 miles per hour is:

A) 0.9576.
B) 0.9960.
C) 0.2467.
D) 0.3520.
E) 0.4659