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प्रश्न
The mean of following numbers is 68. Find the value of ‘x’. 45, 52, 60, x, 69, 70, 26, 81 and 94. Hence, estimate the median.
उत्तर
Mean = `"Sum of all observations"/"Total number of observations"`
∴ `68 = (45 + 52 + 60 + x + 69 + 70 + 26 + 81 + 94)/9`
`=> 68 = (497 + x)/9`
`=>` 612 = 497 + x
`=>` x = 612 – 497
`=>` x = 115
Data in ascending order
26, 45, 52, 60, 69, 70, 81, 94, 115
Since the number of observations is odd, the median is the `((n + 1)/2)^(th)` observation
`=>` Median = `((9 + 1)/2)^(th)` observation = 5th observation.
Hence, the median is 69
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संबंधित प्रश्न
The lengths of 40 leaves of a plant are measured correct to the nearest millimeter, and the data obtained is represented in the following table:
| Length (in mm) | Number of leaves |
| 118 − 126 | 3 |
| 127 – 135 | 5 |
| 136 − 144 | 9 |
| 145 – 153 | 12 |
| 154 – 162 | 5 |
| 163 – 171 | 4 |
| 172 – 180 | 2 |
Find the median length of the leaves.
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| Below 20 | 2 |
| 20 - 25 | 4 |
| 25 - 30 | 18 |
| 30 - 35 | 21 |
| 35 - 40 | 33 |
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| 45 - 50 | 3 |
| 50 - 55 | 6 |
| 55 - 60 | 2 |
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| Size of Farms (in acres) |
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| 5 – 15 | 7 |
| 15 – 25 | 12 |
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| 35 – 45 | 25 |
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| More than 140 | 12 |
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| No. of cars | 11 | 12 | 20 | 7 |
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|
20 less than | 20 – 40 | 40 – 60 | 60 – 80 | 80 – 100 |
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