Final answer:
The ROI for Mechforce Manufacturing for the year was 4.2%
Step-by-step explanation:
The ROI for Mechforce Manufacturing for the year can be calculated by dividing net income by average assets and multiplying by 100. The formula for ROI is: ROI = (Net Income / Average Assets) x 100. Given that the net income is $420,000 and the average assets are $10 million, we can calculate the ROI as follows:
ROI = (420,000 / 10,000,000) x 100 = 4.2%
Therefore, the ROI for the year was 4.2% (option a).