GRAPHING
1,Graphs of a Single Variable
Pie Chart
Bar Graph
Time-Series Graph
Compensation
of employees
(72%)
Corporate
profits
(12%)
Proprietor’s
income
(8%)
Interest
income
(6%)
Rental
income
(2%)This pie chart shows how US national
income is derived from
various sources.
(a) Pie Chart
(b) Bar Graph
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
United
States
United
Kingdom
Mexico India
Income per
Person in 2000
United
States
($34,100)
United
Kingdom
($23,550)
Mexico
($8,790)
India
($2,340)
The bar graph compares
the average income in
four countries.
(c) Time-Series Graph
0
20
40
60
80
100
120
140
- 1950 1960 1970 1980 1990 2000
Productivity
Index
The time-series
graph shows the
productivity of labor
in U.S,businesses
from 1950 to 2000.
2,Graphs of Two Variables,
The Coordinate System
0
0.5
1
1.5
2
2.5
3
3.5
4
0 5 10 15 20 25 30
Albert E,
(25,3.5)
Alfred E,
(5,2.0)
Graph pint average is
measured on the vertical
axis and study time on
the horizontal axis,
Albert E,and Alfred E,
are represented by
various points,We can
see from the graph that
students who study
more tend to get higher
grades.
Grade
Point
Average
Study Time
(hours per week)
3,Curves in the Coordinate System
Income
Price $20,000 $30,000 $40,000
$10 2 novels 5 novels 8 novels
9 6 9 12
8 10 13 16
7 14 17 20
6 18 21 24
5 22 25 28
This table shows the number of novels Emma buys at various
incomes and prices,For any given level of incomes,the data
on price and quantity demanded can be graphed to produce
Emma’s demand curve for novels.
Demand Curve
Quantity of Novels
Purchased
5,10
9,9
13,8
17,7
21,6
25,5
0
2
4
6
8
10
12
0 5 9 13 17 21 25
Price of
Novels
Demand,D1
The line D1 shows how
Emma’s purchases of
novels depend on the
price of novels when
her income is held
constant,Because the
price and the quantity
demanded are
negatively related,the
demand curve slopes
downward.
Shift Demand Curves
Price of
Novels
Quantity of Novels
Purchased
0
2
4
6
8
10
12
0 5 10 15 20 25 30
13 16
When income
increases,the
demand curve shifts
to the right.
When income
decreases,the
demand curve shifts
to the left,D2
Income=
$40,000
D1
Income=
$30,000
D3
Income=
$20,000
When a variable that is not named on either
axis changes,the curve shifts.
4,Slope
0
2
4
6
8
10
12
0 5 9 13 17 21 25
Price of
Novels
Quantity of Novels
Purchased
13,$8
21,$66-8=-2
21-13=8
x
yslop

4 18 21321 86 aaaaaaaaaaaaaaaaaaaaaaaaad i n a t e a a a af i r s t y c o o rxys l o p
first y-coordinate – second y-coordinate
first x-coordinate – second x-coordinate
5,Marginal Change
total utility
all the benefit and satisfaction for the
consumption of goods and services.
marginal utility
quantity changed of the total utility for
adding one unit consumption
CD BREAD
consumption utility consumption utility
0
1
2
3
4
5
6
7
8
9
10
0
50
88
121
150
175
196
214
229
241
250
0
1
2
3
4
5
6
7
8
9
10
0
75
117
153
181
206
225
243
260
276
291
QUANTITY TOTAL
UTILITY
MARGINAL
UTILITY
0
1
2
3
4
5
6
7
8
9
10
0
50
88
121
150
175
196
214
229
241
250
50
38
33
29
25
21
18
15
12
9
0
50
100
150
200
250
300
0 1 2 3 4 5 6 7 8 9 10
U
Q
0
10
20
30
40
50
60
0 1 2 3 4 5 6 7 8 9 10
TU
U
Q
MU
50 38 33 29 25 21 18 15 12 9
TOTAL UTILITY
MARGINAL UTILITY
diminishing marginal utility
- the basic of law of demand
6,Consumer Equilibrium
Principle of utility maximization
that the utility as great as possible
utility-maximizing choice
consumer equilibrium
Conditions of consumer equilibrium
marginal utility per dollar spent
MU/P = 50/6=8.33
MUx MUy
Px Py=
CD TOTAL UTILITY OF
CD & BREAD
BREAD
Q TU Q TU
0
1
2
3
4
5
0
50
88
121
150
175
291
310
313
302
267
175
291
260
225
181
117
0
10
8
6
4
2
0
CD ($6/unit) BREAD ($3/unit)
Q MU MU/P Q MU MU/P
a
b
c
d
e
f
0
1
2
3
4
5
0
50
38
33
29
25
8.33
6.33
5.50
4.83
4.17
10
8
6
4
2
0
15
17
19
28
42
0
5.00
5.67
6.33
9.33
14.00
0
2
4
6
8
10
12
14
16
- 0 1 2 3 4 5
BREAD
CD
POSSIBILITY a b c d e f
MUd
MUc
MUB
6.33 E
7,Marginal Utility and Demand
Price change & Demand
Income change & Demand
CD ($3/unit) BREAD ($3/unit)
Q MUc Q MUB
0
1
2
3
4
5
6
7
8
9
10
16.67
12.67
11.00
9.67
8.33
7.00
6.00
5.00
4.00
3.00
10
9
8
7
6
5
4
3
2
1
0
5.00
5.33
5.67
6.00
6.33
8.33
9.33
12.00
14.00
25.00
6
3
2 5 Q
P
a
b
6
3
5 6 Q
P
d1
d2
Change of CD Change of Bread
CD ($3/unit) BREAD ($6/unit)
Q MUc Q MUB
0
2
4
6
8
10
12.67
9.67
7.00
5.00
3.00
5
4
3
2
1
0
4.17
4.67
6.00
7.00
12.50
6
3
2 5 Q
P
a
b
6
3
5 6 Q
P
d1
d2
Change of CDChange of Bread
Price Effect
CD ($3/unit) BREAD ($6/unit)
Q MUC Q MUB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
16.67
12.67
11.00
9.67
8.33
7.00
6.00
5.00
4.00
3.00
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
5.00
5.33
5.67
6.00
6.33
8.33
9.33
12.00
14.00
25.00
Income Effect