The following table lists U.S. revenue (in $ billions) of the major car-rental companies.
Car-Rental Company ...... Revenue in 2009
Enterprise ........... $10.7
Hertz ............. 4.7
Avis Budget .......... 4.0
Dollar Thrifty ........ 1.5
Other ............. 1.0

a. Construct a relative frequency distribution.
b. Hertz accounted for what percentage of sales?
c. Use Excel to construct a pie chart for these data.