What does the profitability index signify? What is the criterion for judging the worth of investments in the capital budgeting technique based on the profitability index? What is its value, when its...

What does the profitability index signify? What is the criterion for judging the worth of investments in the capital budgeting technique based on the profitability index? What is its value, when its NPV is (a) zero, (b) negative and (c) positive? Also indicate the relationship between IRR and cost of capital in these situations.