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Histogram
A histogram is a data representation that displays grouped data. Grouped data is data that
is collected in intervals.
13
id ou now
The histogram shows the heights of 50 girls.
• The width of each
Heights of Girls bar in a histogram
represents a specific
Frequency 20 the interval 140 -144
interval. For example,
10
covers the range of
0 heights from 140 cm
to 144 cm.
140-144 145-149 150-154 155-159 160-164 • The height of each

Height (cm) bar represents
the frequency in
(a) Find the number of girls with heights from 155 cm to each interval.
159 cm.
(b) A girl with a height of 160 cm and above is eligible to
participate in the volleyball team. Find the number of
girls who are eligible to participate in the volleyball
team. • A histogram does not
(c) By observing the shape of the histogram, make an display the actual
inference based on the distribution of the heights of the values of the data but
displays values in a
girls. certain interval.

• A histogram can
(a) 10 girls provide a display of
There are 3 girls with heights large data sets because
(b) 3 girls of 160 – 164 cm. the data is represented
in class intervals.
(c) Most of the girls have heights of 145 cm to 159 cm.

Frequency polygon
A frequency polygon is a graph formed by joining the midpoint of the top of each bar in
a histogram with straight lines. Based on Example 13, a frequency polygon can be drawn CHAPTER
from the histogram and is shown below.
Heights of Girls Heights of Girls 12
Frequency 20 Frequency 20

10
10
0 0
135-139 140-144 145-149 150-154 155-159 160-164 165-169 135-139 140-144 145-149 150-154 155-159 160-164 165-169

Height (cm) Height (cm)

279
Data Handling

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