The file Audits contains the number of audits of corporations with assets of more than $250 million conducted by the Internal Revenue Service. (Data extracted from K. McCoy, "IRS Audits Big Firms Less Often," USA Today, April 15, 2010, p. 1B.)
a. Plot the data.
b. Fit a three-year moving average to the data and plot the results.
c. Using a smoothing coefficient of W = 0.50, exponentially smooth the series and plot the results.
d. What is your exponentially smoothed forecast for 2010?
e. Repeat (c) and (d), using a smoothing coefficient of W = 0.25.
f. Compare the results of (d) and (e).