The following data show the quarterly sales (in thousands of dollars) for the last three years of operation of Vintage Restaurant in Fort Myers, Florida. The restaurant owner wants to forecast the quarterly sales for the next year .

(a) Construct a time series plot. What type of pattern exists in data?

(b) Use dummy variables and the Excel Regression tool to find a multiple regression model that accounts for seasonal effects in the data.

(c) Based on this model, estimate the quarterly sales for the fourth year.

Year	Quarter	Sales
1	1	252
	2	178
	3	152
	4	202
2	1	263
	2	193
	3	161
	4	212
3	1	255
	2	146
	3	170
	4	210