Sales of a particular product (in thousands of dollars) for the years 2009 through

Sales of a particular product (in thousands of dollars) for the years 2009 through 2012 have been $48,000, $64,000, and $83,000, 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 0.50 for the immediate preceding year and 0.3, 0.15, and 0.05 for the three years before that?