FedEx and United Parcel Service (UPS) are the world's two leading cargo carriers by volume and revenue (The Wall Street Journal, January 27th, 2004). According to the Airports Council International, the Memphis International Airport (FedEx) and the Louisville International Airport (UPS) are two of the ten largest cargo airports in the world. The following random samples show the tons of cargo per day handled by these airports. Data are in thousands of tons.
Excel or Minitab users: The data set is available in file named Cargo. All data sets can be found on the premium online website.
Compute the sample mean (to 1 decimal) and sample standard deviation (to 2 decimals) for each aiport.
Memphis (FedEx) Louisville (UPS)
Sample mean
Sample standard deviation
What is the point estimate of the difference between the two population means (to 1 decimal)?
Interpret this value in terms of the higher-volume airport and a comparison of the volume difference between the two airports.
is the higher volume airport, handling more than times the volume of the other.
Develop a 95% confidence interval of the difference between the daily population means for the two airports (to 2 decimals).