Suppose you are told that a 95% confidence interval for the average price of a gallon of regular gasoline in your state is from $3.05 to $3.92. Use the fact that the confidence interval for the mean is in the form x − E to x + E to compute the sample mean and the maximal margin of error E. (Round your answers to two decimal places.)

The sample mean is 3.48 and the margin of error is 0.44.

Step-by-step explanation:

We know that the confidence interval is written in the form "x − E to x + E", meaning x: sample mean or estimator, and E: margin of error.

To calculate the mean, we can calculate the average of both bounds of the confidence interval:

With one of the bounds, we can calculate the margin of error E