Exercises 11.98 through 11.104 use the CROPS data file, which contains the U.S. yield (bushels/acre) of corn and soybeans from 1957-2013.23

Question 11.99

11.99 Can soybean yield predict corn yield?

Run the simple linear regression using soybean yield to predict corn yield.

crops

  1. Summarize the results of your analysis, including the significance test results for the slope and for this model.
  2. Analyze the residuals with a Normal quantile plot. Is there any indication in the plot that the residuals are not Normal?
  3. Plot the residuals versus year. Does the plot indicate that year might be useful in a multiple linear regression with soybean yield to predict corn yield? Explain your answer.

11.99

. (a) . There is a significant simple linear regression between corn yield and soybean yield; soybean yield can significantly predict corn yield. . (b) The Normal quantile plot shows that the residuals are mostly Normal but have a slight right-skew. (c) There is somewhat of a relationship between the residuals and year, suggesting that it might be useful in the model with soybean yield to predict corn yield.