Using the data from TABLES 1, 2 and 3 below, plot the following graphs:

(i) On one set of axes plot the 2 curves of:

total sales revenue against volume of sales

total costs against volume of sales.

The volume of sales should be on the x-axis (values from 20 to 26).

On a second set of axes plot the 3 graphs:

marginal cost against volume of sales marginal revenue against volume of sales

price against volume of sales.

Again the volume of sales should be on the x-axis (values from 20 to 26).

Price	Volume of Sales	Total sales revenue	Marginal revenue
80	20	800
76	21	836	36
72	22	864	28
68	23	884	20
64	24	896	12
60	25	900	4
56	26	896	4

TABLE 1

Price	Volume of Sales	Total costs	Marginal cost
80	20	720
76	21	728	8
72	22	740	12
68	23	756	16
64	24	776	20
60	25	800	24
56	26	828	28

TABLE 2

Price	Volume of Sales	Total sales revenue	Total cost	Profit
80	20	800	720	80
76	21	836	728	108
72	22	864	740	124
68	23	884	756	128
64	24	896	776	120
60	25	900	800	100
56	26	896	828	68

TABLE 3 (a) From your graphs determine the maximum profit and optimum volume of sales.

(b) What do you notice about:

the marginal cost and marginal revenue lines

total cost and total revenue curves at maximum profit.