The data below (stored in Drive-Thru Speed) represent the average time (in seconds) it took to be served at the drive-through at McDonald's from 1998 to 2012:

a. Plot the time series.
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 2013?
e. Repeat (c) and (d), using W = 0.25.
f. Compare the results of (d) and (e)?

Drive-Through Drive-Through Year Speed (seconds)Year Speed (seconds) 1999 2000 2001 2002 2003 )(M 2005 177.59 167.02 169.88 170.85 162.72 156.92 32.52 167.90 2006 2007 2008 2009 2010 2011 2012 163.90 167.10 158.77 174.22 179.27 184.20 188.83