suppose on a highway with a speed limit of 65mph the speed o

suppose on a highway with a speed limit of 65mph the speed of cars are independent and normally distrubted with an average speed = 65mph and a standard deviation = 5 mph. what is the standard deviation for the sample mean speed in a random sample of n = 10 cars?

a. 1.58

b. 13

c. 32.5

Solution

The standard error of the mean is given by

se = s / sqrt(n)

= 5 / sqrt(10)

= 1.58113883

= 1.58 [ANSWER, A]