Mathematics
In a study of diabetic patients, the following data was obtained :
| Age (in years) | No. of patients |
|---|---|
| 10 - 20 | 3 |
| 20 - 30 | 8 |
| 30 - 40 | 30 |
| 40 - 50 | 36 |
| 50 - 60 | 27 |
| 60 - 70 | 15 |
| 70 - 80 | 6 |
Represent the above data by a histogram and a frequency polygon.
Answer
Frequency distribution table :
| Age (in years) | Class marks | No. of patients |
|---|---|---|
| 10 - 20 | 15 | 3 |
| 20 - 30 | 25 | 8 |
| 30 - 40 | 35 | 30 |
| 40 - 50 | 45 | 36 |
| 50 - 60 | 55 | 27 |
| 60 - 70 | 65 | 15 |
| 70 - 80 | 75 | 6 |
Steps of construction of histogram :
Take 1 cm along x-axis = 10 years.
Take 1 cm along y-axis = 6 patients.
Construct rectangles corresponding to the above continuous frequency distribution table.
The required histogram is shown in the adjoining figure.
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 the first end point with the mid-point of class 0 - 10 with zero frequency, and join the other end point with the mid-point of class 80 - 90 with zero frequency.
The required frequency polygon is shown by thick line segments in the diagram.
Related Questions
Construct a combined histogram and frequency polygon for the following data :
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