#### Transcript of An introduction to Histograms

**An introduction to Histograms**

**Starter**

Which one of these charts is the odd one out?

Why?

What is a histogram?

A histogram is a bar graph that shows how frequently data occur within certain ranges or intervals. The height of each bar gives the frequency density for the respective interval

**Solution**

In order to draw the Histogram we draw a graph (with the bars touching) of frequency density/speed

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Age

Drawing a histogram

Frequency density

WILT

Recognise a histogram

Calculate the frequency density

Draw a histogram

5

4

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2

1

To calculate the frequency density we use the following formula:

Calculating the frequency density

Frequency density =

Frequency

Class width

0.25

1.5

1.8

4

7

2

We cannot use a bar chart because we have continuous data.

We need to find the frequency density in order to draw a histogram

Mileage (m) Frequency Frequency density

0 ≤ m < 5 10

5 ≤ m < 15 40

15 ≤ m < 20 50

20 ≤ m < 30 70

30 ≤ m < 45 60

45 ≤ m < 50 40

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4

10

7

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5 10 15 20 25 30 35 40 45 50

Frequency density

Mileage (m)

0.25

1.5

1.8

4

7

2

Full transcript