Problem:
Company "A" has a beta of 1.5 and a cost of capital of 25%. Company "B" has a beta of 0.8 and a cost of capital of 15%. When evaluated at a rate of 15%, the project shows an NPV of +$5 million, and when evaluated at a rate of 25%, the project shows an NPV of -$2 million.
Explain comprehensively and also provide formulas and calculations.