An economist examines the relationship between changes in short-term interest rates and long-term interest rates. He believes that changes in short-term rates are significant in explaining long-term interest rates. He estimates the model Dlong = β0 + β1 Dshort + ε , where Dlong is the change in the long-term interest rate (10-year Treasury bill) and Dshort is the change in the short-term interest rate (3-month Treasury bill). Monthly data from January 2006 through December 2010 were obtained from the St. Louis Federal Reserve's website. A portion of the regression results are shown below (n = 60):
Use a 5% significance level in order to determine whether there is a linear relationship between Dshort and Dlong.