COURSE 3 LESSON 10-2
Reading Graphs Critically
Use the graph below.
a. Which day appears to have almost twice
the earnings of Monday?
Thursday, because it extends up
about 15 units as compared with
Monday’s 8 units.
b. Why might the graph appear misleading?
The break in the vertical scale makes the differences between daily
earnings appear greater than they are. For example, Thursday’s
earnings were about $81, while Monday’s earnings were $74.
The graph, however, gives the impression that Thursday’s earnings
were twice as great as Monday’s.
10-2
COURSE 3 LESSON 10-2
Reading Graphs Critically
Using different scales, make two bar graphs for the
data. Use a break symbol in only one of the graphs.
Quarter Mile Records
Car
Dragster
Indy car
Sprint car
Time(s)
5
8
9
NASCAR stock car
Stock Pontiac Bonneville
10
17
The highest time is 17 seconds.
Label the vertical axis with multiples of 5 from 0 to 20.
10-2
COURSE 3 LESSON 10-2
Reading Graphs Critically
(continued)
Quarter Mile Records
Car
Dragster
Indy car
Sprint car
Time(s)
5
8
9
NASCAR stock car
Stock Pontiac Bonneville
10
17
The data start at 5 seconds. Label the vertical axis with multiples of 2.5,
beginning with 5. Use a break symbol.
10-2
COURSE 3 LESSON 10-2
Reading Graphs Critically
1. What can be used to give a graph a misleading visual impression?
Sample: a break in an axis scale
2. The average daily temperature of a town varies from 55°F to 98°F.
Describe an appropriate scale you could use to create a bar graph for
the data.
Sample: Break between 0 and 50. Show 50º, 55º, 60º, 65º, 70º, 75º,
80º, 85º, 90º, 95º, and 100º on the axis.
10-2