An analyst examines the effect that various variables have on crop yield. He estimates the following model: y = ?0 + ?1 x1 + ?2 x2 + ?3 x3 + ? Where y is the average yield in bushels per acre, x1 is the amount of summer rainfall, x2 is the average daily use in machine hours of tractors on the farm, and x3 is the amount of fertilizer used per acre. A portion of the regression results is shown in the accompanying table. a. Predict the crop yield per acre if x1 is 5, x2 is 4, and x3 is 0.5. b. Calculate the standard deviation of the difference between the actual crop yield and the estimate of the crop yield. c. How much of the variation in crop yield is unexplained by the model? (Round answers to 3 decimal places.) Capture.PNG

lession Analysis Saved Where y is the average yield in bushels per acre, x1 Is the amount of summer rainfall, x2 is the average daily use in machine hours of tractors on the farm, and x3 is the amount of fertilizer used per acre. A portion of the regression results is shown in the accompanying table. df SS MS F Regression 3 12,000 4000 10 Residual 9 2,400 400 Total 9 14,400 Coefficients Standard Error t-stat p-value Intercept 1.6 1 1.6 0.1232 X1 7.5 2.5 3 0.0064 6 4 1.5 0.1472 X3 1 0.5 2 0.0574 a. Predict the average crop yield per acre if x1 is 5, x2 is 4, and x3 is 0.5. 63.6 bushels per acre b. Calculate the standard deviation of the difference between the actual crop yield and the estimate of the crop yield. 17.321 bushels per acre c. How much of the variation in crop yield is unexplained by the model? (Enter the answer as a percentage rounded to 1 decimal place.) 16.7 %