•
The
relative frequency
for the subgroup is:
Relative frequency
= Subgroup count / Total
count.
26

◼
To express relative frequencies in terms of
percentages, multiply each proportion by 100%.
◼
Note that the total of the proportions must add to
1.0 and the total of the percentages must add to
100%.
2.1 Summarizing Qualitative Data
LO 2.1
Weather
Frequency
Relative Frequency
Percentage
Cloudy
1
1/28=0.036
x 100=
3.6%
Rainy
20
20/28=0.714
x 100=71.4%
Sunny
7
7/28=0.250
x 100=25.0%
Total
28
28/28=1.000
x 100=100%
27

Example 2.1: Describing 2006 Jeep Purchasing
Patterns
•
Table 2.1 lists all 251 vehicles sold in 2006 by
the greater Cincinnati Jeep dealers
•
Table 2.1 does not reveal much useful
information
•
A frequency distribution is a useful summary
–
Simply count the number of times each model
appears in Table 2.1
28

•
Table 2.1 lists all 251 vehicles sold in 2006
•
by the greater Cincinnati Jeep dealers
29