4. To help Enterprise Industry predict a more accurate future monthly demand for its Fresh product, please construct six following linear regression models(please report its 2, 2,and coefficients of 0,1,2,3) 1 = 0 + 11 2 = 0 + 22 3 = 0 + 33 4 = 0 + 11 + 22 5 = 0 + 11 + 33 6 = 0 + 11 + 22 + 33 Compare those 6 models and comment which model gives a better prediction of demand for Fresh.

Month Price IndPrice PriceDif AdvExp Demand X1 X2 X4 X3 Y 1 3.85 3.80 -0.05 5.50 7.38 2 3.75 4.00 0.25 6.75 8.51 3 3.70 4.30 0.60 7.25 9.52 4 3.70 3.70 0.00 5.50 7.50 5 3.60 3.85 0.25 7.00 9.33 6 3.60 3.80 0.20 6.50 8.28 7 3.60 3.75 0.15 6.75 8.75 8 3.80 3.85 0.05 5.25 7.87 9 3.80 3.65 -0.15 5.25 7.10 10 3.85 4.00 0.15 6.00 8.00 11 3.90 4.10 0.20 6.50 7.89 12 3.90 4.00 0.10 6.25 8.15 13 3.70 4.10 0.40 7.00 9.10 14 3.75 4.20 0.45 6.90 8.86 15 3.75 4.10 0.35 6.80 8.90 16 3.80 4.10 0.30 6.80 8.87 17 3.70 4.20 0.50 7.10 9.26 18 3.80 4.30 0.50 7.00 9.00 19 3.70 4.10 0.40 6.80 8.75 20 3.80 3.75 -0.05 6.50 7.95 21 3.80 3.75 -0.05 6.25 7.65 22 3.75 3.65 -0.10 6.00 7.27 23 3.70 3.90 0.20 6.50 8.00 24 3.55 3.65 0.10 7.00 8.50 25 3.60 4.10 0.50 6.80 8.75 26 3.65 4.25 0.60 6.80 9.21 27 3.70 3.65 -0.05 6.50 8.27 28 3.75 3.75 0.00 5.75 7.67 29 3.80 3.85 0.05 5.80 7.93 30 3.70 4.25 0.55 6.80 9.26