1. You NEED your book!!! Frequency Distribution
April 12, 2012

2. What is Frequency Distribution?

3. What is Frequency Distribution?
Frequency Distribution is a convenient system for organizing large amounts of data.
A number of classes determined, and all values in a class are tallied and grouped together
The most common way of displaying frequency distributions is by using a histogram
Histogram: a type of bar graph in which the width of each bar represents a class interval (the range of each class) and the height of the bar represents the frequency in that interval
Class Limits: the upper and lower values in each interval
Class Marks: the midpoints of the classes (the average of the upper and lower limits)
Retail Management Testing Scores
Scores
Frequency
60-70
70-80
80-90
90-100 9 10 12 3
Class interval
60≤𝑠<70
Classes

4. Find the range of the data b) Determine an appropriate class interval
Example 1: The winning scores for the first 38 Super Bowls are: 35, 33, 16, 23, 16, 24, 14, 24, 16, 21, 32, 27, 35, 31, 27, 26, 27, 38, 38, 46, 39, 42, 20, 55, 20, 37, 52, 30, 49, 27, 35, 31, 34, 23, 34, 20, 48, 32
Find the range of the data b) Determine an appropriate class interval
Find the class marks d) Construct a frequency distribution of the data
e) Draw a histogram of the data
Winning Score
Tallies
Frequency

5. Example 1: The winning scores for the first 38 Super Bowls are: 35, 33, 16, 23, 16, 24, 14, 24, 16, 21, 32, 27, 35, 31, 27, 26, 27, 38, 38, 46, 39, 42, 20, 55, 20, 37, 52, 30, 49, 27, 35, 31, 34, 23, 34, 20, 48, 32
f) What conclusions can you determine from the graph?

6. Assignment: pg. 894 #10 & 11