Construction of a Histogram of a Continuous Grouped Frequency Distribution with Unequal Class Interv
Construction of a Histogram of a Continuous Grouped Frequency Distribution with Unequal Class Interval.
Procedure to Construct :-
1. Take a graph and draw two perpendicular lines. Mark them as OX and OY.
2. Take horizontal line OX as x-axis and vertical line OY as y-axis.
3. Choose suitable scale for class intervals on x-axis and represent class limits.
4. Choose a suitable scale along y-axis to represent frequencies.
5. Construct rectangle with class intervals as base and heights proportional to the frequencies
Following are the ages of 180 patients getting medical treatment in a hospital on a day.
Age (in years) |
0-5 |
5-10 |
10-20 |
20-30 |
30-40 |
40-60 |
60-80 |
No of patients |
25 |
25 |
20 |
30 |
20 |
40 |
20 |
Represent the above datas by histograms.
In this example the class intervals are not equal. The minimum class interval is 5-0 = 5. The maximum class size is 20. We shall find the adjustable frequency by the formula as follows.
Adjusted frequency of a class = Ã— class frequency
Adjusted frequencies of the data will be :
Age of (in years) |
No. of patients |
Adjusted frequency |
0 - 5 |
25 |
Ã— 25 = 25 |
5 - 10 |
25 |
Ã— 25 = 25 |
10 - 20 |
20 |
Ã— 20 = 10 |
20 - 30 |
30 |
Ã— 30 = 15 |
30 - 40 |
20 |
Ã— 20 = 10 |
40 - 60 |
40 |
Ã— 40 = 10 |
60 - 80 |
20 |
Ã— 20 = 5 |