(a) Construct a time series plot. What type of pattern exists in the data?(b) Use a regression model with dummy variables as follows to develop an equation to account for seasonal effects in the data: Qtr1=1 if quarter 1, 0 otherwise; Qtr2=1 if quarter 2, otherwise 0; Qtr3=1 if quarter 3, 0 otherwise. (c) Based on the model you developed in past (b), compute the quarterly forecasts for next year.