Stat 2-3 Other Types of Graphs

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Other Types of
Graphs
Section 2.3
Objective 3
Represent data using;
1) Pareto Charts
2) Time series graphs
3) Pie graphs
4) Stem and Leaf

Pareto Charts
puh-RAY-toe, or
pah-RAY-toe.
A Pareto Chart is used to represent a
frequency distribution for a categorical
variable, and the frequencies are
displayed by the heights of vertical bars,
which are arranged in order from highest
to lowest.
Example 2-8
State
Number
Indiana
2.9¢
Oklahoma
4.3¢
Florida
6.0¢
Maine
3.8¢
Pennsylvania
5.8¢
Construct and analyze a Pareto chart for the data.
Time Series Graph

A Time Series graph represents data that
occur over a specific period of time.
Compound time series
Example 2-9
The number (in millions)
of vehicles, both
passenger and
commercial, that used the
Pennsylvania Turnpike
for the years 1999
through 2003 is shown.
Construct and analyze a
time series graph for the
data.
Year
Number
1999
156.2
2000
160.1
2001
162.3
2002
172.8
2003
179.4
Pie Graph
A pie graph is a circle that is divided into
sections or wedges according to the
percentage of frequencies in each
category of the distribution.
Example 2-10
This frequency
distribution shows the
number of pounds
(millions) of each
snack food eaten
during the Super
Bowl. Construct a pie
graph for the data.
Snack
Pounds
frequency
(millions)
Chips
11.2
Tortilla C.
8.2
Pretzels
4.3
Popcorn
3.8
Snack Nuts
2.5
Total n=
30.0
How to construct a pie graph
1. Step 1: If raw data is given, construct a frequency
distribution.
2. Step 2: Convert frequency into degrees.
f

Degrees   360
n
Example 2-11
Construct a pie graph
showing the blood types
of the army inductees
The frequency distribution
is repeated here:
Class
Freq.
%
A
5
20
B
7
28
O
9
16
AB
4
16
n
25
100
Misleading Graphs
Stem and Leaf Plots
A stem and leaf plot is a data plot that
uses part of the data value as the stem
and part of the data value as the leaf to
form groups or classes
Back to Back stem and leaf
Example 2-12
At an outpatient testing center, the number of
cardiograms performed each day for 20 days is shown.
Construct a stem and leaf plot for the data.
25
31
20
32
13
14
43
20
57
23
36
32
33
32
44
32
52
44
51
45
Example 2-13
An insurance Company researchers conducted a survey on
the number of car thefts in a large city for a period of 30 days
last summer. The raw data are shown. Construct a stem and
leaf plot by using classes 50-54, 55-59, 60-64, 65-69, 70-74,
and 75-79
52
58
75
79
57
65
62
77
56
59
51
53
51
66
55
68
63
78
50
53
67
65
69
66
69
57
73
72
75
55
pictograph
Homework:
 Exercises
2-3 page 84
#3,7,12,14, 15 and 17 plus
 Extending Concepts #20-25 all
 Create a Graph
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