decimal places.) R2=Ra2= (b) Does the estimated regression equation provide a good fit to the data? Explain. Considering the nature of the data, being able to explain slightly [ than 50% of the variability in the number of runs given up per inning pitched using just two independent variables is [. Since ] than 50% of the variability in the ERA can be explained by the linear effect of home runs per inning pitched (HR/IP) and strike-outs per inning pitched (SO/IP), this is considering the complexity of predicting pitching performance..