I dont understand this. Could someone explain this to me? Thank you

Sales of tablet computers at Ted Glickman's electronics store in Washington, D.C., over the past 10 weeks are shown in the table below: Week 1 2 3 4 5 6 7 8 9 10 Demand 20 21 29 37 26 29 35 20 26 30 a) The forecast for weeks 2 through 10 using exponential smoothing with a = 0.60 and a week 1 initial forecast of 20.0 are (round your responses to two decimal places): Week 1 2 3 4 5 6 7 8 9 10 Demand 20 21 29 37 26 29 35 20 26 30 Forecast 20.0 20 20.6 25.64 32.46 28.58 28.83 32.53 25.01 25.60 b) For the forecast developed using exponential smoothing (