The quarterly sales data (number of copies sold) for a college textbook over the past threeyears follow.Quarter Year 1 Year 2 Year XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX 2615a. Construct a time series plot....

The quarterly sales data (number of copies sold) for a college textbook over the past threeyears follow.Quarter Year 1 Year 2 Year 31 1690 1800 18502 940 900 11003 2625 2900 29304 2500 2360 2615a. 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 accountfor seasonal effects in the data: Qtr1  1 if Quarter 1, 0 otherwise; Qtr2  1 ifQuarter 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.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 accountfor any seasonal effects in the data: Qtr1  1 if Quarter 1, 0 otherwise; Qtr2  1if Quarter 2, 0 otherwise; Qtr3  1 if Quarter 3, 0 otherwise.c. Compute the quarterly forecasts for next year.d. Let t  1 to refer to the observation in quarter 1 of year 1; t  2 to refer to the observationin quarter 2 of year 1; . . . and t  12 to refer to the observation in quarter 4 ofyear 3. Using the dummy variables defined in part (b) and t, develop an estimatedregression equation to account for seasonal effects and any linear trend in the timeseries. Based upon the seasonal effects in the data and linear trend, compute the quarterlyforecasts for next year.