r^2

R-squared indicates the precentage of the variation in Y that can be explained by the variation in X.

Coefficients: EstimateStd. Error t value Pr(>|t|) (Intercept) 4.7446 16.8714 0.281 0.780 Age 0.2962 0.6414 0.462 0.647 Residual standard error: 16.45 on 33 degreesoffreedom Multiple R-squared: 0.00642, AdjustedR-squared: -0.02369 F-statistic: 0.2132 on 1 and 33 DF, p-value: 0.6473

In this case 0,000642 or 0,6 % of the variation in km from UMB can be explained by Age of the EDS 115 student.