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Forecast Error Exercise 1
    Your company produces and distributes two lines of Consumer Extermal Hard Drives: 1 Terabyte drives (1 Tb) and 5 Terabyte Drives (5 Tb). The unit sales levels and forecasts for the last two previous years are in the table below. For this exercise, You have been asked to calculate the Forecast error and Forecast Percentage error for (a) each type of terabyte (b) each year, and (c) for each two-year period. Start your analysis by completing the table below, then use the spaces below (in light green) to calculate the error and percent error for each question asked. These equations and an example are covered in your textbook on pages 107 - 111. Finally, in the last space, provide a written summary of your findings regarding the sales trends and the forecasting efficacy by year, by product, and overall.
    Year    Period    1 Tb Forecast    1 Tb Actual    1 Tb Error     1 TB % Error    5 Tb Forecast    5 Tb Actual    5 Tb Error    5 Tb % Error
    1    1    1000    800    -200    -25.0%    500    350    -150    -42.9%
        2    1100    950    -150    -15.8%    550    400    -150    -37.5%
        3    1300    1100    -200    -18.2%    650    700    50    7.1%
        4    2200    2000    -200    -10.0%    1100    1200    100    8.3%
        5    2300    2150    -150    -7.0%    1150    1300    150    11.5%
        6    3000    2750    -250    -9.1%    1500    1600    100    6.3%
        7    3500    3200    -300    -9.4%    1750    1900    150    7.9%
        8    3600    3300    -300    -9.1%    1800    2200    400    18.2%
        9    3200    3000    -200    -6.7%    1600    1700    100    5.9%
        10    2200    1900    -300    -15.8%    1100    1200    100    8.3%
        11    2100    2000    -100    -5.0%    1050    1100    50    4.5%
        12    4200    3300    -900    -27.3%    2100    2250    150    6.7%
    Year 1    Sum            -3250    -158%            1050    4.4%
    Year...