5.47 The paper "Crop Improvement for Tropical and Subtropical Australia: Designing Plants for Difficult Climates" (Field Crops Research (1991]: 113–139) gave the following data on x = crop duration...

Extracted text: 5.47 The paper "Crop Improvement for Tropical and Subtropical Australia: Designing Plants for Difficult Climates" (Field Crops Research (1991]: 113–139) gave the following data on x = crop duration (in days) for soy- beans and y = crop yield (in tons per hectare): 92 100 102 96 1.9 92 y 1.7 2.3 2.0 1.5 102 106 106 121 143 1.7 1.6 1.8 1.0 0.3 Σ 1060 Ey = 15.8 a = 5.20683380 E xy = 1601.1 b = -0.3421541 a. Construct a scatterplot of the data. Do you think the least-squares line will give accurate predictions? Explain. b. Delete the observation with the largest x value from the sample and recalculate the equation of the least-squares line. Does this observation greatly affect the equation of the line? c. What effect does the deletion in Part (b) have on the value of r2? Can you explain why this is so?