FSA Study session 8 query

All, Wanted to know the difference of treatment between marginal tax rate and average tax rate in one of Concept checkers in study session 8. While calculating NI from EBIT - they have charged average tax rate However, calculating after tax bond interest, they have charged marginal tax rate Please advise. Thanks, Jimit

when calculating net income you consider average of the tax rate that on the revenues that created that net income because interest expense is deductible, it reduces the portion of income just before being taxed,that is the portion of income that puts the company in the highest tax bracket, that’s why you consider the marginal tax rate for after tax bond interest. This is an assumption I am making, waiting for other opinions