Import the FlightDelays data set (see Case Study in Section 1.1) into R. Although the data represent all flights for United Airlines and American Airlines in May and June 2009, assume for this exercise that these flights are a sample from all flights flown by the two airlines under similar conditions. We will compare the lengths of flight delays between the two airlines.
(a) Create exploratory plots of the lengths of delays for the two airlines.
(b) Find a 95% t confidence interval for the difference in mean flight delays between the two airlines and interpret this interval