$$R^{2} = r^{2} = 0.86^{2} = 0.7396$$ 
\textbf{In the setting of the previous problem, about what percent of the variation in the number of service calls is explained by the linear relation between number of service calls and number of machines?~} 
Options:
[a] 86\% 
[b] 93\% 
[c] 74\% 
[d] None of the above 
[e] \textbf{Can't tell from the information given} 