Are gasoline prices higher during the height of the summer vacation season than at other times? The

Question:

Are gasoline prices higher during the height of the summer vacation season than at other times? The data in GasPrice give the mean monthly prices (in dollars per gallon) for unleaded gasoline in the United States from January 2006 to April 2010.
a. Construct a time-series plot.
b. Develop an exponential trend forecasting equation with monthly components.
c. Interpret the monthly compound growth rate.
d. Interpret the monthly multipliers.
e. Write a short summary of your findings.