Question 3.In the sheet sales of the Excel file, you can find the sales (in millions of dollars) of Gigy Computer each year from 1987 to 2020.

Part A. (3.5 points) Develop a linear regression equation for the given data using Excel formulas, and write the corresponding values of the intercept and the slope in the sheet labeled Part A in the Excel file .

Part B. (5 points) Using the regression line you found in Part A above, forecast the dollar amount in sales for the years between 1987 2020 in the sheet labeled in Part B in the Excel file .

Part C. (5 points) Using a two-period moving averages model, forecast the total dollar amount in sales for the years between 1987 and 2020 in the sheet labeled in Part C in the Excel file

Part D. (3 points) Using a one-period moving averages model, forecast the total dollar amount in sales for the years between 1987 and 2020 in the sheet labeled in Part D in the Excel file

Part E. (3.5 points) Using a five-period moving averages model, forecast the total dollar amount in sales for the years between 1987 and 2020 in the sheet labeled in Part E in the Excel file

Part F. (5 points) Determine, among the models you have developed in Part B, Part C, Part D, and Part E above, which one provides the best forecast using the MAD method in the sheet labeled Part F in the Excel file Why do you think this model is the best? Explain briefly.

sales Part A 101 Sales of Gigy Year Sales 2020 150 2019 151 2018 162 2017 2016 2015 2014 2013 2012 2011 146 2010 115 2009 105 2008 110 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 115 1989 1988 106 1987 102 87 77 sales Part Sales 150 151 162 Year 2020 2019 2018 2017 2016 2015 2014 2013 148 126 150 2012 137 146 115 105 110 130 124 124 116 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 146 120 137 102 115 87 106 sales Part A 101 Sales of Gigy Year Sales 2020 150 2019 151 2018 162 2017 2016 2015 2014 2013 2012 2011 146 2010 115 2009 105 2008 110 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 115 1989 1988 106 1987 102 87 77 sales Part Sales 150 151 162 Year 2020 2019 2018 2017 2016 2015 2014 2013 148 126 150 2012 137 146 115 105 110 130 124 124 116 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 146 120 137 102 115 87 106