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प्रश्न
Thirty children were asked about the number of hours they watched T.V. programmers in the previous week. The results were found as follows:
| 1 | 6 | 2 | 3 | 5 | 12 | 5 | 8 | 4 | 8 |
| 10 | 3 | 4 | 12 | 2 | 8 | 15 | 1 | 17 | 6 |
| 3 | 2 | 8 | 5 | 9 | 6 | 8 | 7 | 14 | 12 |
(i) Make a grouped frequency distribution table for this data, taking class width 5 and one of the class intervals as 5 – 10.
(ii)How many children watched television for 15 or more hours a week?
उत्तर
(i) Class intervals will be 0-5,5-10,10-15,............
The grouped frequency distribution table is as follows
| Hours | Number of children |
| 0-5 | 10 |
| 5-10 | 13 |
| 10-15 | 5 |
| 15-20 | 2 |
| Total | 30 |
(ii) The number of children, who watched TV for 15 or more hours a week is 2 (i.e.,number of children in class interval 15-20 ).
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संबंधित प्रश्न
The heights of 50 students, measured to the nearest centimeters, have been found to be as follows:-
| 161 | 150 | 154 | 165 | 168 | 161 | 154 | 162 | 150 | 151 |
| 162 | 164 | 171 | 165 | 158 | 154 | 156 | 172 | 160 | 170 |
| 153 | 159 | 161 | 170 | 162 | 165 | 166 | 168 | 165 | 164 |
| 154 | 152 | 153 | 156 | 158 | 162 | 160 | 161 | 173 | 166 |
| 161 | 159 | 162 | 167 | 168 | 159 | 158 | 153 | 154 | 159 |
(i) Represent the data given above by a grouped frequency distribution table, taking the class intervals as 160 - 165, 165 - 170, etc.
(ii) What can you conclude bout their heights from the table?
A study was conducted to find out the concentration of sulphur dioxide in the air in parts per million (ppm) of a certain city. The data obtained for 30 days is as follows:-
| 0.03 | 0.08 | 0.08 | 0.09 | 0.04 | 0.17 |
| 0.16 | 0.05 | 0.02 | 0.06 | 0.18 | 0.20 |
| 0.11 | 0.08 | 0.12 | 0.13 | 0.22 | 0.07 |
| 0.08 | 0.01 | 0.10 | 0.06 | 0.09 | 0.18 |
| 0.11 | 0.07 | 0.05 | 0.07 | 0.01 | 0.04 |
(i) Make a grouped frequency distribution table for this data with class intervals as 0.00 - 0.04, 0.04 - 0.08, and so on.
(ii) For how many days, was the concentration of sulphur dioxide more than 0.11 parts per million?
Thirty children were asked about the number of hours they watched TV programmes in the previous week. The results were found as follows:-
| 1 | 6 | 2 | 3 | 5 | 12 | 5 | 8 | 4 | 8 |
| 10 | 3 | 4 | 12 | 2 | 8 | 15 | 1 | 17 | 6 |
| 3 | 2 | 8 | 5 | 9 | 6 | 8 | 7 | 14 | 12 |
(i) Make a grouped frequency distribution table for this data, taking class width 5 and one of the class intervals as 5 - 10.
(ii) How many children watched television for 15 or more hours a week?
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| 2.6 | 3.0 | 3.7 | 3.2 | 2.2 | 4.1 | 3.5 | 4.5 |
| 3.5 | 2.3 | 3.2 | 3.4 | 3.8 | 3.2 | 4.6 | 3.7 |
| 2.5 | 4.4 | 3.4 | 3.3 | 2.9 | 3.0 | 4.3 | 2.8 |
| 3.5 | 3.2 | 3.9 | 3.2 | 3.2 | 3.1 | 3.7 | 3.4 |
| 4.6 | 3.8 | 3.2 | 2.6 | 3.5 | 4.2 | 2.9 | 3.6 |
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812, 840, 885, 835, 836, 878, 840, 868, 890, 806, 840, 890.
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| Age (in years): |
10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 |
| No. of Patients: |
90 | 50 | 60 | 80 | 50 | 30 |
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