Question

rainfall and corn crop yield reported for the 38 years from 1890 through 1927 give us the scatterplot shown below with an r = 0.0426. yield is the number of ears of corn measured in metric tons per hectare, rainfall is in inches. based on corn crop yield from ezekiel, m. and k. a. fox. (1959). methods of correlation and regression analysis. wiley: new york. the plot shows a positive linear relationship between the inches of rainfall and the size of the corn yield. which of the following is an appropriate interpretation of the relationship in the data shown above? a. the more rain, the lower the yield of corn. b. the growth rate of corn is positively affected by more rainfall. c. rainfall seems to have a positive effect on the yield of corn.

Explanation:

• Option A: Incorrect. The scatter - plot shows a positive trend (as \(r = 0.0426>0\)), not a negative one.
• Option B: Incorrect. The data is about yield (number of ears of corn per hectare), not growth rate.
• Option C: Correct. Since \(r = 0.0426>0\) (a positive correlation coefficient) and the scatter - plot shows an upward trend (though weak), rainfall seems to have a positive effect on the yield of corn.

Answer:

C. Rainfall seems to have a positive effect on the yield of corn.