Please help me with part d. The quarterly sales data (number of copies sold) for a college textbook over the past three years follow. Quarter Year 1 Year 2 Year 3 1,749 1,700 1,774 WNP 975 827 1,011 2,636 2.918 2.985 2,418 2.446 2.661 a. Construct a time series plot.b. Use the following dummy variables to develop an estimated regression equation to account for any seasonal effects in the data: Qtrl = 1 if Quarter 1, 0 otherwise; Qtr2 = 1 if Quarter 2, 0 otherwise; Qtr3 = 1 if Quarter 3, 0 otherwise. Round your answers to whole number and enter negative value as negative number. Value - 2508 + -767 Qtri + -1571 @ Qtr2 + 338 Qtr3 c. Compute the quarterly forecasts for next year. Round your answers to whole number. Quarter 1 forecast 1741 0 Quarter 2 forecast 938 Quarter 3 forecast 2846 Quarter 4 forecast 2508 d. Let t = 1 to refer to the observation in quarter 1 of year 1; t= 2 to refer to the observation in quarter 2 of year 1; . . . and t= 12 to refer to the observation in quarter 4 of year 3. Using the dummy variables defined in part (b) and t, develop an estimated regression equation to account for seasonal effects and any linear trend in the time series. Round your answers to whole number and enter negative value as negative number. (Use unrounded values for intermediate calculations.) The regression equation is Value - 2345 + -706 Qtr1 + -1530 Qtr2 + 358 @ Qtr3 + 20@t Based upon the seasonal effects in the data and linear trend, compute the quarterly forecasts for next year. Round your answers to whole number. Quarter 1 forecast 1659 X Quarter 2 forecast 835 x Quarter 3 forecast 2723 X Quarter 4 forecast 2365 x