Question

The tread life of tires mounted on light-duty trucks follows the normal probability distribution with a population mean of 60,000 miles and a population 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?

Answer 1

Answer: 632.46

Explanation:

The formula to calculate the standard error is given by :-

`S.E.=(\sigma)/(√(n))`

Given : The tread life of tires mounted on light-duty trucks follows the normal probability distribution with a population mean of 60,000 miles and a population standard deviation of 4,000 miles.

i.e.
`\sigma= 4000`

Also, sample size : n=40

Then standard error of the mean will be :-

`S.E.=(4000)/(√(40))=632.455532034\approx632.46`