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प्रश्न
The following table shows the number of saplings planted by 30 students. Fill in the boxes and find the average number of saplings planted by each student.
| No. of saplings (Scores) xi |
No. of students (frequency) fi |
fi x xi |
| 1 | 4 | 4 |
| 2 | 6 | `square` |
| 3 | 12 | `square` |
| 4 | 8 | `square` |
| N = `square` | ∑fixi = `square` |
Mean `bar "x"` = `square/"N"`
= `square/square`
= `square`
∴ The average number of trees planted `square`
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उत्तर
| No. of saplings (Scores) xi |
No. of students (frequency) fi |
fi×xi |
| 1 | 4 | 4 |
| 2 | 6 | = 2 × 6 = 12 |
| 3 | 12 | = 3 × 12 = 36 |
| 4 | 8 | = 4 × 8 = 32 |
| N = 30 | ∑fixi = 84 |
Mean `bar "x"` = `bb((sum f_ix_x))/"N"`
= `bb(84/30)`
= 2.8
∴ The average number of trees planted is 2.8.
संबंधित प्रश्न
Mean of 100 observations is 40. The 9th observation is 30. If this is replaced by 70 keeping all other observations same, find the new mean.
The following table shows the electricity (in units) used by 25 families of Eklara village in a month of May. Complete the table and answer the following questions.
| Electricity used (units) `bb(x_i)` |
No. of Families (frequency) `bb(f_i)` |
`bb(f_ix_i)` |
| 30 | 7 | _________ |
| 45 | 2 | __________ |
| 60 | 8 | __________ |
| 75 | 5 | __________ |
| 90 | 3 | __________ |
| N = _________ | `sum f_ix_i` = ______ |
- How many families use 45 units electricity?
- State the score, the frequency of which is 5.
- Find N, and `sum f_ix_i`
- Find the mean of electricity used by each family in the month of May.
A batsman scored the following number of runs in six innings: 36, 35, 50, 46, 60, 55. Calculate the mean runs scored by him in an inning.
The mean weight of 4 members of a family is 60 kg. Three of them have the weight 56 kg, 68 kg and 72 kg respectively. Find the weight of the fourth member
The mean of a set of seven numbers is 81. If one of the numbers is discarded, the mean of the remaining numbers is 78. The value of discarded number is
The mean of the square of first 11 natural numbers is
The average of the marks 2, 9, 5, 4, 4, 8, 10 is ____________
Find the mean of the following data.
5.1, 4.8, 4.3, 4.5, 5.1, 4.7, 4.5, 5.2, 5.4, 5.8, 4.3, 5.6, 5.2, 5.5
Calculate the Mean, Median and Mode of the following data:
5, 10, 10, 12, 13.
Are these three equal?
In a class of 100 students there are 70 boys whose average marks in a subject are 75. If the average marks of the complete class is 72, then what is the average of the girls?
