Question: The following data show the number of rental cars in service for three rental car companies: Hertz, Avis, and Dollar. The data are for the year 2007-2010 and are in thousands of vehicles (Auto Rental News website, May 15,2011).
a. Construct a time series graph far the years 2007 to 2010 showing the number of rental cars in service for each company. Show the time series for all three companies on the same graph.
b. Comment on who appears to be the market share leader and how the market shares are changing over time.
c. Construct a bar chart showing rental cars in service for 2010. Is this chart based on cross-sectional or time series data?