A random sample of 36 drivers used on average 749 gallons of gasoline per year. If the standard deviation of the population is 332, find the 95% confidence interval of the mean for all drivers.

Answer 1

You need to use this formula:

Mean +/- CI * (sd/ sqrt(number of observations))

in you text book the eq look like this:

X_bar +/- Z (s/ sqrt(n))