If you know the sample size (n) = 225, the average number of miles driven by WSU students is 12,000 (x) and the standard deviation is 3000 miles (s). Find the interval of miles within which 95% of the drivers fall. Make sure to use standard error in your calculation.

I know that the answer is 11608 to 12392.

I am unsure how to arrive at this answer, I am looking for the proper formula and how to use it to solve this problem.

Thank you!