Suppose an agronomist used four test plots to determine the relationship between the wheat yield y (in bushels per acre) and the amount of fertilizer x (in hundreds of pounds per acre). The results are shown in the table. Determine the least squares regression line for the data using the regression capabilities of a graphing utility, and then use this model to estimate the yield for a fertilizer application of 160 pounds per acre. Round your answer to one decimal place.
A) 37.3 bushels per acre
B) 39.7 bushels per acre
C) 35.6 bushels per acre
D) 38.4 bushels per acre
E) 39.3 bushels per acre

Question

Suppose an agronomist used four test plots to determine the relationship between the wheat yield y (in bushels per acre) and the amount of fertilizer x (in hundreds of pounds per acre). The results are shown in the table. Determine the least squares regression line for the data using the regression capabilities of a graphing utility, and then use this model to estimate the yield for a fertilizer application of 160 pounds per acre. Round your answer to one decimal place. 
A) 37.3 bushels per acre 
B) 39.7 bushels per acre 
C) 35.6 bushels per acre 
D) 38.4 bushels per acre 
E) 39.3 bushels per acre

Quizplus · Accepted Answer

Using regression capabilities of a graphing utility, the least squares regression equation is found to be: 
y = 29.03 + 0.1891x 
Plugging in x = 1.6 (converted from 160 pounds per acre to hundreds of pounds per acre) gives an estimated yield of: 
y = 29.03 + 0.1891(1.6) = 38.41 or 38.4 bushels per acre (rounded to one decimal place). 
Therefore, the best choice is D.

Suppose an Agronomist Used Four Test Plots to Determine the Relationship