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प्रश्न
If the arithmetic mean, 7, 8, x, 11, 14 is x, then x =
विकल्प
9
9.5
10
10.5
उत्तर
The given observations are 7, 8, x, 11, 14.
Mean = x (Given)
Now,
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संबंधित प्रश्न
To find out the concentration of SO2 in the air (in parts per million, i.e., ppm), the data was collected for 30 localities in a certain city and is presented below:
| concentration of SO2 (in ppm) | Frequency |
| 0.00 − 0.04 | 4 |
| 0.04 − 0.08 | 9 |
| 0.08 − 0.12 | 9 |
| 0.12 − 0.16 | 2 |
| 0.16 − 0.20 | 4 |
| 0.20 − 0.24 | 2 |
Find the mean concentration of SO2 in the air.
The following table gives the number of branches and number of plants in the garden of a school.
| No. of branches (x) | 2 | 3 | 4 | 5 | 6 |
| No. of plants (f) | 49 | 43 | 57 | 38 | 13 |
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The number of students absent in a class were recorded every day for 120 days and the information is given in the following frequency table:
| No. of students absent (x) | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| No. of days (f) | 1 | 4 | 10 | 50 | 34 | 15 | 4 | 2 |
Find the mean number of students absent per day.
Find the mean of each of the following frequency distributions: (5 - 14)
| Class interval | 0 - 6 | 6 - 12 | 12 - 18 | 18 - 24 | 24 - 30 |
| Frequency | 6 | 8 | 10 | 9 | 7 |
If the mean of the following frequency distribution is 18, find the missing frequency.
| Class interval | 11 – 13 | 13 – 15 | 15 – 17 | 17 – 19 | 19 – 21 | 21 – 23 | 23 – 25 |
| Frequency | 3 | 6 | 9 | 13 | f | 5 | 4 |
The algebraic sum of the deviations of a frequency distribution from its mean is always ______.
If the mean of first n natural numbers is \[\frac{5n}{9}\], then n =
Find the mean of the following distribution:
| Class interval | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 |
| Frequency | 10 | 6 | 8 | 12 | 5 |
The Mean of n observation x1, x2,..., xn is `bar"X"`. If (a - b) is added to each of the observation, show that the mean of the new set of observation is `bar"X"` + (a - b).
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| Weight (in kg) | 100 – 110 | 110 – 120 | 120 – 130 | 130 – 140 | 140 – 150 |
| Number of wrestlers |
4 | 14 | 21 | 8 | 3 |
Find the mean weight of the wrestlers.
