Final answer:
When comparing mutually exclusive projects of different scales, the dollar impact of each investment must be considered, rather than percentage returns.
Step-by-step explanation:
When comparing mutually exclusive projects which have different scales, you must know the dollar impact of each investment rather than percentage returns.
This is true because the dollar impact represents the actual amount of money gained or lost from the investment, while percentage returns only measure the relative gain or loss in comparison to the initial investment.
For example, if Project A has a percentage return of 10% and an initial investment of $100,000, while Project B has a percentage return of 8% and an initial investment of $1,000,000, Project B would have a higher dollar impact because the 8% return on $1,000,000 is larger than the 10% return on $100,000.