Develop your forecast for window fans for each month of the next year, 2015. I am looking for the formulas to put into the blank boxes, not just the numbers. Please help

2015 Work Seasonality Seasonality Seasonality Seasonality Avg. 2015 Month 2011 2012 2013 2014 Avg.Dly Days Index Index Index Index Seasonality | Forecast Production 21 61,294 44,261 35,720 69,238 52,628.250 20 63,659 71,182 42,846 73,816 62,875.750 W N 22 17,144 52,895 27,772 34,858 33,167.250 21 30,831 47,786 56,943 40,519 44,019.750 20 23,763 43,688 35,287 18,746 30,371.000 6 22 19,001 11,452 35,631 20,989 21,768.250 7 22 20,011 50,165 66,414 39,405 43,998.750 8 21 22,070 51,648 34,121 56,888 41,181.750 9 21 17,534 24,537 53,058 38,232 33,340.250 10 22 59,568 45,899 82,018 75,578 65,765.750 11 19 92,429 51,087 66,824 75,674 71,503.500 12 21 81,020 46,460 61,272 67,821 64,143.250 Totals 252 508,324 541,060 597,906 611,764 Monthly Avg. 42,360 45,088 49,826 50,980 Linear Regression Year Demand Y = a + bX 1 508,324 b = slope 541,060 a = Y-intercept W N 597,906 X = Independent Variable 5 5th Year 611,764 Y = Dependent Variable Forecast of 2016 Annual Demand 5