Histogram and Frequency Polygon Lesson

Histogram and Frequency Polygon Lesson

Elizabeth Borres

At the end of the lesson, students will be able to:

1. Display data in pictorial form.

2. Show FDT through Histogram and Frequency Polygon.

Multiple Choice

How many employees have a salary less than $22,000?

• 50

• 350

• 0

• 10

Multiple Choice

How many people watched more than 6 hours of TV?

• 10

• 5

• 20

• 17

Multiple Choice

Which interval has the greatest number of students?

• 48-51

• 56-59

• 60-63

• 64-67

Multiple Choice

Which interval has the greatest number of employees?

• 11-21

• 33-43

• 77-87

• 44-54

Histogram

Graph that displays the data by using vertical bars of various heights to represent the frequencies of the classes.

To Construct a Histogram

1. Draw and label the x and y axis.

2. Represent the frequency on the y-axis and the class boundaries on the x-axis.

3. Using the frequencies as the heights, draw the vertical bars for each class.

Frequency Polygon

• Graph that uses lines that connect the points plotted for the frequencies at the midpoint of the classes; frequencies are represented by the heights of the points.

To Construct a Frequency Polygon

• Find the midpoints of each class.

• Draw the x and y axes. Label the x-axis with the midpoint of each class then use a suitable scale for the frequencies on the y-axis.

• Using the midpoints for the x values and the frequencies on the y-axis.

To Construct a Frequency Polygon

• Connect adjacent points with the line segments.

• Draw the line back to the x-axis at the beginning and the end of the graph (where the next midpoints would be located).

Poll

Do you have any questions?

Multiple Choice

To create a histogram for this data, what would go along the x-axis?

• Frequency

• Science

• Number of students

Multiple Choice

Which of the following is represented by the histogram?

• Of the 20 riders represented in the graph, over 50% are 30 years of age or older.

• One fourth of the riders represented in the graph are younger than 40 years old.

• Half the riders represented in the graph are between the ages 10-29.

• Six percent of the riders represented in the graph are between the ages 10 and 19.

Multiple Choice

Is a histogram the same as a bar graph?

• Yes, because they both use intervals.

• No, because a histogram displays numerical data while a bar graph displays categorical data.

• Yes, because they both use bars to display data.

• No, because a histogram displays categorical data while a bar graph displays numerical data.

Multiple Choice

Which interval has the greatest number of students?

• 48-51

• 56-59

• 60-63

• 64-67

Multiple Choice

What is the most number of times that someone visited the cinema?

• 5

• 1

• 35

• 2

Multiple Choice

How many people have a shoe size of 6?

• 17

• 18

• 19

• 15.4

Multiple Choice

What is the range of the shoe sizes?

• 5

• 4

• 16

• 9