CR10.3 The article “Flyers Trapped on Tarmac Push for Rules on Release” (USA Today, July 28, 2009) included the accompanying data on the number of flights with a tarmac delay of more than 3 hours between October 2008 and May 2009 for U.S. airlines.

Airline Number of Flights Rate per 100,000 Flights AirTran 7 0.4 Alaska 0 0.0 American 48 1.3 American Eagle 44 1.6 Atlantic Southeast 11 0.6 Comair 29 2.7 Source: USA TODAY. June 3, 2009.

Cumulative Review Exercises CR10.1 - CR10.16 Airline Number of Flights Rate per 100,000 Flights Continental 72 4.1 Delta 81 2.8 ExpressJet 93 4.9 Frontier 5 0.9 Hawaiian 0 0.0 JetBlue 18 1.4 Mesa 17 1.1 Northwest 24 1.2 Pinnacle 13 0.7 SkyWest 29 0.8 Southwest 11 0.1 United 29 1.1 US Airways 46 1.6

a. Construct a dotplot of the data on number of flights delayed for more than 3 hours. Are there any unusual observations that stand out in the dot plot? What airlines appear to be the worst in terms of number of flights delayed on the tarmac for more than 3 hours?

b. Construct a dotplot of the data on rate per 100,000 flights. Write a few sentences describing the interesting features of this plot.

c. If you wanted to compare airlines on the basis of tarmac delays, would you recommend using the data on number of flights delayed or on rate per 100,000 flights?

Explain the reason for your choice.