Mat 318                                                                                                                  

Lab 6: Linear regression and correlation

 

Please open worksheet WEATHER2.

 

  1. Make a scatterplot of Rochester vs. Syracuse. (Let x=Syracuse, y=Rochester.) Does there seem to be a linear relationship? How strong?

 

 

  1. Find correlation between Rochester and Syracuse.

 

 

  1. Find the equation of the least squares line that can be used to predict temperature in Rochester as a function of temperature in Syracuse.

 

 

 

  1. Suppose that one day you measure 50 F in Syracuse. What would be the predicted temperature in Rochester? Use correct notation!

 

 

 

 

  1. Now let’s say you find out later that the actual temperature in Rochester was 70F. Find the residual. Use correct notation!

 

 

 

 

 

  1. Explore the relationships between various columns, making scatterplots and computing correlation. You should try to get an intuitive feel for how the coefficient reflects the scatterplot.

 

 

 

 

  1. Try to generate two columns with correlation equal to

 

a)      –1

 

b)      between –0.6 and –0.3