The tread life of tires mounted on light-duty trucks follows the normal probability distribution with a mean of 60,000 miles and a standard deviation of 4,000 miles. Suppose we select a sample of 40 tires and use a simulator to determine the tread life. What is the standard error of the mean?
A)632.46
B)40
C)4000
D)Cannot be determineD.

Question

Quizplus · Accepted Answer

The standard error of the mean (SEM) is calculated by dividing the standard deviation by the square root of the sample size. In this case, SEM = 4000 / sqrt(40) = 632.46.

The Tread Life of Tires Mounted on Light-Duty Trucks Follows