Question

a random sample of 35 four - door passenger vehicles had a mean gas mileage, in miles per gallon (mpg), of 25.9 mpg. the estimate had a margin of error of 2.6 mpg at a 98% confidence level. of the following, which is the most plausible value for the true mean gas mileage of all four - door passenger vehicles?
choose 1 answer
a 24 mpg
b 29 mpg
c 32 mpg
d 35 mpg

Explanation:

Step1: Calculate the confidence interval

The confidence interval is given by the formula: \(\text{Confidence Interval}=\bar{x}\pm E\), where \(\bar{x}\) is the sample mean and \(E\) is the margin of error.
Here, \(\bar{x} = 25.9\) mpg and \(E=2.6\) mpg.
So, the lower limit is \(25.9 - 2.6=23.3\) mpg and the upper limit is \(25.9+2.6 = 28.5\) mpg.

Answer:

A. \(24\) mpg