7) A book store has historical demand (Thousands) for the book An Inventory Story and The TSP Mystery for the past 12 months as shown in the table below. Month An Inventory Story The TSP Mystery 1 10.50 12.61 2 12.01 16.01 3 9.77 15.77 4 10.20 18.19 5 9.44 19.90 6 11.40 23.40 7 9.72 23.66 8 9.90 25.90 9 9.01 27.70 10 10.20 30.20 11 10.90 33.68 12 8.89 32.98 Answer the following questions. In solving this problem, you can use an order of N=5 with moving average, use ==0.2 as the parameters needed for exponential smoothing and double exponential smoothing (Holt's method). (15 points) a) Describe the trend of the historical demand data for An Inventory Story