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प्रश्न
The number of Science and Mathematics projects submitted by Model high school, Nandpur in last 20 years at the state level science exibition is:
2, 3, 4, 1, 2, 3, 1, 5, 4, 2, 3, 1, 3, 5, 4, 3, 2, 2, 3, 2. Prepare a frequency table and find the mean of the data.
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उत्तर
The frequency table of the data is as follows:
| Number of projects `bb((x_i))` | Frequency `bb((f_i))` | `bb(f_ix_i)` |
| 1 | 3 | 1 x 3 = 3 |
| 2 | 6 | 2 x 6 = 12 |
| 3 | 6 | 3 x 6 = 18 |
| 4 | 3 | 4 x 3 = 12 |
| 5 | 2 | 5 x 2 = 10 |
| ∑f = 20 | `sum f_ix_i` = 55 |
Since the mean of the data = `(sum f_ix_i)/(sumf)"`
`= 55/20`
= 2.75
Hence, the mean of the data is 2.75.
संबंधित प्रश्न
Following table shows the points of each player scored in four games:
| Player | Game 1 | Game 2 | Game 3 | Game 4 |
| A | 14 | 16 | 10 | 10 |
| B | 0 | 8 | 6 | 4 |
| C | 8 | 11 | Did not play | 13 |
Now answer the following questions:
- Find the mean to determine A’s average number of points scored per game.
- To find the mean number of points per game for C, would you divide the total points by 3 or by 4? Why?
- B played in all the four games. How would you find the mean?
- Who is the best performer?
The data 6, 4, 3, 8, 9, 12, 13, 9 has mean 9.
Solve any two of the following.
Find the mean of the data given in the following table.
| Class | 0-20 | 20-40 | 40-60 | 60-80 | 80-100 |
| Frequency | 6 | 4 | 5 | 7 | 3 |
The mean of five numbers is 50, out of which mean of 4 numbers is 46, find the 5th number:
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`
The algebraic sum of the deviations of a set of n values from their mean is
If the mean of five observations x, x + 2, x + 4, x + 6, x + 8, is 11, then the mean of first three observations is
The mean of 5, 9, x, 17 and 21 is 13, then find the value of x
The mean of the data 12, x, 28 is 18. Find the value of x
Mean can never be a fraction.
