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: Recall confidence - interval formula

The confidence - interval for the population mean $\mu$ is given by $\bar{x}-E<\mu<\bar{x} + E$, where $\bar{x}$ is the sample mean and $E$ is the margin of error.

Step2: Calculate the lower and upper bounds

We are given that $\bar{x}=25.9$ mpg and $E = 2.6$ mpg.
The lower bound is $\bar{x}-E=25.9 - 2.6=23.3$ mpg.
The upper bound is $\bar{x}+E=25.9 + 2.6=28.5$ mpg.

Answer:

A. 24 mpg