Frequency Histogram

How to make and solve a frequency historam: 2 examples and their solutions.

Example 1

Example

Solution

Draw a rectangular form like this.

The given frequency table shows
the intervals of the test scores
and their frequencies.

So write Test Scores
at the bottom of the form.

And write Frequency
on the left side of the form.

Write the intervals of the test scores
at the bottom of the form.

The frequencies are from 2 to 7.

So write 0 to 8
on the left side of the form.

And inside the rectangle,
lightly draw horizontal lines
that show each frequency.

The frequency of the interval 50-59 is 2.

So, for 50-59,
draw a vertical bar
whose height is 2.

The frequency of the interval 60-69 is 3.

So, for 60-69,
draw a vertical bar
whose height is 3.

Draw the bar right next to the previous bar
so that
there would be no space between the bars.

The frequency of the interval 70-79 is 7.

So, for 70-79,
draw a vertical bar
whose height is 7.

The frequency of the interval 80-89 is 6.

So, for 80-89,
draw a vertical bar
whose height is 6.

The frequency of the interval 90-99 is 2.

So, for 90-99,
draw a vertical bar
whose height is 2.

So this is the frequency histogram
of the given test scores.

Example 2

Example

Solution

The students whose scores are less than 70
are these two bars.

So the number of the students is,
add the heights of the bars,
3 + 6.

3 + 6 = 9

So 9 is the answer.