10. The following data are for the Akron Division of Consolidated Rubber, Inc.:

Sales	$	840,000
Net operating income	$	54,000
Average operating assets	$	340,000
Stockholders' equity	$	84,000
Residual income	$	24,000

For the past year, the margin used in ROI calculations was:

9.10%

10.00%

6.43%

9.29%