Reading Graphs Critically

1
Reading Graphs Critically
COURSE 3 LESSON 10-2
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 Mondays 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, Thursdays earnings were
about 81, while Mondays earnings were 74.
The graph, however, gives the impression that
Thursdays earnings were twice as great as
Mondays.
10-2
2
Reading Graphs Critically
COURSE 3 LESSON 10-2
Using different scales, make two bar graphs for
the data. Use a break symbol in only one of the
graphs.
Quarter Mile Records
10-2
3
Reading Graphs Critically
COURSE 3 LESSON 10-2
(continued)
Quarter Mile Records
10-2
4
Reading Graphs Critically
COURSE 3 LESSON 10-2
1. What can be used to give a graph a misleading
visual impression? 2. The average daily
temperature of a town varies from 55F to 98F.
Describe an appropriate scale you could use to
create a bar graph for the data.
Sample a break in an axis scale
Sample Break between 0 and 50. Show 50º, 55º,
60º, 65º, 70º, 75º, 80º, 85º, 90º, 95º, and 100º
on the axis.
10-2