Question: Question 5:

In 2003, the average passenger vehicle in the United States was driven 11.3 thousands miles, as reported by the U.S. Federal Highways Administration in the Highway Statistics. A random sample of 500 passenger vehicles revealed a mean of 11.1 thousand miles driven for last year and a standard deviation of 6.0 thousand miles.

(a) At a 5% significance level, do the data provide sufficient evidence to conclude that the last year’s mean distance driven is different than in 2003?

(b) Find a 95% confidence interval for the population mean.

(c) Does the value of 11.3 thousand miles, hypothesized for the mean in the null hypothesis in (a), lie within your confidence interval from part (b)? Why or why not?