Complete this assignment using R Markdown.

A company with a large fleet of cars wants to study the gasoline usage. They check the gasoline usage for 50 company trips chosen at random, finding a mean of 25.02 mpg. Based on the past experience, they believe the standard deviation of the general gasoline usage is 4.83 mpg.

(a) Which kind of confidence intervals is appropriate to use here, z-interval or tinterval?

(b) Use R to find the critical value they need when constructing a 95% confidence interval.

(c) Use R to construct at 95% confidence interval for the mean of the general gasoline usage. (d) If they want to control the width of the confidence interval to be within 0.8 mpg, at least how many trips do they have to sample? Use R to calcluate.