Mathematics
The ages (in years) of 360 patients treated in a hospital on a particular day are given below :
| Age in years | No. of patients |
|---|---|
| 10 - 20 | 90 |
| 20 - 30 | 40 |
| 30 - 40 | 60 |
| 40 - 50 | 20 |
| 50 - 60 | 120 |
| 60 - 70 | 30 |
Draw a histogram and a frequency polygon on the same graph to represent the above data.
Answer
Frequency distribution table :
| Age in years | Class marks | No. of patients |
|---|---|---|
| 10 - 20 | 15 | 90 |
| 20 - 30 | 25 | 40 |
| 30 - 40 | 35 | 60 |
| 40 - 50 | 45 | 20 |
| 50 - 60 | 55 | 120 |
| 60 - 70 | 65 | 30 |
Steps of construction of histogram :
Take 1 cm along x-axis = 10 years.
Take 1 cm along y-axis = 10 patients.
Construct rectangles corresponding to the above continuous frequency distribution table.
Steps of construction of frequency polygon:
Mark the mid-points of upper bases of rectangles of the histogram.
Join the consecutive mid-points by line-segments.
Join first end point with mid-point of class 0 - 10 with zero frequency, and join the other end point with the mid point of class 70 - 80 with zero frequency.
The required frequency polygon is shown by thick line segments in the diagram.
Related Questions
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