Explain the difference between marginal and average tax rates, and identify which of these rates is used

Question:

Explain the difference between marginal and average tax rates, and identify which of these rates is used in and why.

Capital Budgeting
Capital budgeting is a practice or method of analyzing investment decisions in capital expenditure, which is incurred at a point of time but benefits are yielded in future usually after one year or more, and incurred to obtain or improve the...