3 . Assume that a firm has a plant of fixed size and employs . The table below shows the relationships the marginal product of labour, and the average (a )Assume each unit of labour costs the firm $20 the firm might employ. and enter these figure (b )Now determine the marginal cost of the firm's the table. (c)If labour is the only variable input , the tot average variable cost of the firm's product. ( d )Describe the relationship between the mar gina product . (e )Describe the relationship between the average