Need help with solving questions b and c manually (without using statistical software or Excel).

Shop Now Month11 = I II NovelLiver 0 otherwise Other than this change, the multiple regression approach for handling seasonality remains the same. EXERCISES . . . .'. . .. . . . . . . . . Methods 28. Consider the following time series. Quarter Year 1 Year 2 Year 3 71 68 62 49 41 51 A W N - 58 60 53 78 81 72 a. Construct a time series plot. What type of pattern exists in the data? b. Use the following dummy variables to develop an estimated regression equation to account for seasonal effects in the data: Qtr1 = 1 if Quarter 1, 0 otherwise; Qtr2 = 1 if Quarter 2, 0 otherwise; Qtr3 = 1 if Quarter 3, 0 otherwise. c. Compute the quarterly forecasts for next year. 29. Consider the following time series data. Year 3