Draw a histogram for the daily earnings of 30 drug stores in the following table:
| Daily earning (in Rs): |
450-500 | 500-550 | 550-600 | 600-650 | 650-700 |
| Number of Stores: | 16 | 10 | 7 | 3 | 1 |
Solution
To represent the given data by a histogram, we first draw horizontal and vertical axes. Let us consider that the horizontal and vertical axes represent the class-intervals and the frequencies of the class-intervals respectively.
The given data is a continuous grouped frequency distribution with equal class-intervals. Construct rectangles with class-intervals as bases and respective frequencies as heights. The scale for horizontal axis may not be same as the scale for vertical axis. Let us take one vertical division is equal to 1 unit.
The heights of the different rectangles are as follows:
1. The height of the rectangle corresponding to the class-interval 450-500 is 16 big divisions.
2. The height of the rectangle corresponding to the class-interval 500-550 is 10 big divisions.
3. The height of the rectangle corresponding to the class-interval 550-600 is 7 big divisions.
4. The height of the rectangle corresponding to the class-interval 600-650 is 3 big divisions.
5. The height of the rectangle corresponding to the class-interval 650-700is 1 big divisions.
The histogram of the given data is as follows:
