Data collected on the yearly registrations for a Six Sigma

Data collected on the yearly registrations for a Six Sigma seminar at the Quality College are shown in the following table:
a) Develop a 3-year moving average to forecast registrations from year 4 to year 12.
b) Estimate demand again for years 4 to 12 with a 3-year weighted moving average in which registrations in the most recent year are given a weight of 2, and registrations in the other 2 years are each given a weight of 1.
c) Graph the original data and the two forecasts. Which of the two forecasting methods seems better?