# A simple bivariate regression of crop yield on rainfall.

Please execute an example where regression could be used to show a relationship between two variables.

© BrainMass Inc. brainmass.com October 9, 2019, 11:42 pm ad1c9bdddfhttps://brainmass.com/statistics/regression-analysis/simple-bivariate-regression-crop-yield-rainfall-264911

#### Solution Preview

In showing a relationship between two variables we are usually guided by theory initially. For example, suppose I am a nut farmer in the Medina valley in California. I have been farming for close to 20 years and I notice that my nuts tend to grow best when annual rainfall is not too much and not too little. In fact, I may have collected nut yield and weather data for 20 years for my region and suspect that holding all other things constant such as fertilizer, pest control, etc. I get the greatest yield when annual rainfall is somewhere around 18". If it rains more than that then my yield drops off and if it rains less than that my yield drops off. Suppose i have collected data on my yield over 20 years as well. For simplicity we'll assume that the soil, ...

#### Solution Summary

The following uses a data set on crop yield and rainfall and demonstrates a method of fitting a quadratic regression equation to the data set.