Please use EXCEL and show me how you computed the formulas.

12.7. The Oceanside Hotel is adjacent to City Coliseum, a 24,000 seat arena that is home to the city's professional basketball and ice hockey teams and that hosts a variety of concerts, trade shows, and conventions throughout the year. The hotel has experienced the following occupancy rates for the nine years since the coliseum opened: Compute an exponential smoothing forecast with =.20, an adjusted exponential smoothing forecast with =.20 and =.20, and a linear trend line forecast. Compare the three forecasts using MAD and average error (E), and indicate which forecast seems to be most accurate