Given below are the steps to be followed.
Step 1: Mark class intervals on Xaxis and frequencies on Yaxis.
Step 2: The scale of both the axes should not be same.
Step 3: . If the intervals are in inclusive form, convert them to the exclusive form.
Step 4: Draw rectangles with class intervals as bases and the corresponding frequencies as heights.
Step
5: To draw the histogram for an ungrouped frequency distribution of a
variate we should assume the frequency corresponding to the variate
value x is spread over the interval x$\frac{h}{2}$ to x+$\frac{h}{2}$.h:jump from one value
to the next.
Solved Examples
Question 1: A die is tossed 11 times and the outcomes are recorded {1, 2, 2, 3, 3, 3, 3, 4, 4, 5, 6}. Construct an histogram for this data.
Solution:
We see that the graph peaks at 3,
Mean = 3.27
Median
= Mode = 3. We see that the numbers are distributed about the mean. The
distribution of this graph is wide compared to size of the peak,
indicating that values in the set are only loosely bunched round the
mean.
Frequency

Frequency Count 
1

1 
2 
2 
3 
4 
4 
2 
5 
1 
6 
1 
Question 2: Given below is the data of 50 employees working in an Max. Wealth life Insurance company, Plot histogram for the given data.
Class Interval

Frequency

1120 
8 
2130 
12 
3140 
8 
4150 
12 
5160 
5 
6170 
5 
Solution:
As the class Intervals are Inclusive we have to convert them into the exclusive form.
Class Interval 
Frequency

10.520.5 
8 
20.530.5 
12 
30.540.5 
8 
40.550.5 
12 
50.560.5 
5 
60.570.5 
5 
The histogram for the above data is shown below: