The Index of Exposure to Radioactive Waste and the Cancer

Essay

The index of exposure to radioactive waste and the cancer mortality rates (deaths per 100,000)were recorded for nine different geographic regions.Explain what the R-squared in this regression means.
Dependent variable is: Cancer Mortality Rate
R-squared = 85.8%
s = 14.00993 with 9 - 2 = 7 degrees of freedom $$\begin{array} { l l l l l } \text { Variable } & \text { Coefficient } & \text { SE(Coeff) } & \text { t-ratio } & \text { P-value } \\\text { Constant } & 114.7156 & 8.045663 & 14.25807 & 0.00000198 \\\text { Index of Exp } & 9.231456 & 1.418787 & 6.506584 & 0.000332\end{array}$$