What is the relationship between

What is the relationship between supply price of investment, prospective yield and marginal efficiency of capital?

The relationship between supply price of investment, prospective yield and marginal efficiency of capital is given by the equation:
MEK= Prospective yield / Supply Price x 100
Where, MEK = Marginal efficiency of capital The above equation states that MEK and yield have a positive relation, while supply price and MEK are negatively related.