Sales of a particular product (in thousands of dollars) for the years 2009 through 2012 have been 45, 54, 65, and 73, respectively.
a) What sales would you predict for 2013 using a simple four-year moving average?
b) What sales would you predict for 2013 using a weighted moving average with weights of 0.40 for the immediate preceding year and 0.25, 0.20, and 0.15 for the three years before that?