The relation among marginal utility, total utility and average utility can be understood by a careful study of Table 4.1 and Fig. 4.1. It is clear from this table and figure that initially the total utility curve slopes upwards to the right.This indicates that the total utility will rise with consumption of additional units of the commodity. However, the increase in total utility is not constant, but falls steadily. In other words, the total utility rises at a falling rate. This is shown by corresponding downward or negative slope of the marginal utility curve. In the present example, this happens upto 6 units of the commodity.When the total utility reaches its maximum value, marginal utility becomes zero. Before this point, though marginal utility falls, it always remains positive. In our…