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प्रश्न
Find the mean of the following frequency distribution by the short cut method :
| Class | 1-10 | 11-20 | 21-30 | 31-40 | 41-50 | 51-60 | 61-70 |
| Frequency | 7 | 10 | 14 | 17 | 15 | 11 | 6 |
उत्तर
| Class Interval | xi | fi | A = 35.5 d = x - A |
fid |
| 1-10 | 5.5 | 7 | -30 | -210 |
| 11-20 | 15.5 | 10 | 20 | -200 |
| 21-30 | 25.5 | 14 | -10 | -140 |
| 31-40 | A = 35.5 | 17 | 0 | 0 |
| 41-50 | 45.5 | 15 | 10 | 150 |
| 51-60 | 55.5 | 11 | 20 | 220 |
| 61-70 | 65.5 | 6 | 30 | 180 |
| Total | 80 | 0 |
`barx = A + (Σf_i d)/(Σf_i)`
`barx = 35.5 + 0/80`
`barx = 35.5 + 0`
`barx = 35.5`
∴ Mean = 35.5
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संबंधित प्रश्न
Calculate the mean of the following distribution :
| Class Interval | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
| Frequency | 8 | 5 | 12 | 35 | 24 | 16 |
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| Marks | 5 | 6 | 7 | 8 | 9 |
| Number of Students | 6 | a | 16 | 13 | b |
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| 121 – 130 | 12 |
| 131 – 140 | 16 |
| 141 – 150 | 30 |
| 151 – 160 | 20 |
| 161 – 170 | 14 |
| 171 – 180 | 8 |
Find the median height by drawing an ogive.
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