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Question
The relative humidity (in %) of a certain city for a month of 30 days was as follows:-
| 98.1 | 98.6 | 99.2 | 90.3 | 86.5 | 95.3 | 92.9 | 96.3 | 94.2 | 95.1 |
| 89.2 | 92.3 | 97.1 | 93.5 | 92.7 | 95.1 | 97.2 | 93.3 | 95.2 | 97.3 |
| 96.2 | 92.1 | 84.9 | 90.2 | 95.7 | 98.3 | 97.3 | 96.1 | 92.1 | 89 |
(i) Construct a grouped frequency distribution table with classes
84 - 86, 86 - 88
(ii) Which month or season do you think this data is about?
(iii) What is the range of this data?
Solution
(i) A grouped frequency distribution table of class size 2 has to be constructed. The class intervals will be 84 − 86, 86 − 88, and 88 − 90…
By observing the data given above, the required table can be constructed as follows.
| Relative humidity (in %) | Number of days (frequency) |
| 84 − 86 | 1 |
| 86 − 88 | 1 |
| 88 − 90 | 2 |
| 90 − 92 | 2 |
| 92 − 94 | 7 |
| 94 − 96 | 6 |
| 96 − 98 | 7 |
| 98 − 100 | 4 |
| Total | 30 |
(ii) It can be observed that the relative humidity is high. Therefore, the data is about a month of rainy season.
(iii) Range of data = Maximum value − Minimum value
= 99.2 − 84.9 = 14.3
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