sir, i have watched all the free lectures, but i have a doubt in high low method the variable cost per unit that we calculate, can be used to calculate the fixed costs only for the highest and lowest units of production. why not for the others?
As I explain in the lectures, the problem is that it assumed the relationship is perfectly linear. If it were, then it would work for all the others. In practice the relationship will not be perfectly linear, which is why regression analysis is much better.
Calculations on regression analysis are no longer examinable in Paper PM, but you should remember the idea from Paper F2 (or from university if you were exempt from Paper F2).