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प्रश्न
The mean of first fifteen even numbers is ____________
पर्याय
4
16
5
10
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उत्तर
16
Explanation;
Hint:
`(2 + 4 + 6 + .... + 30)/15 = (2[1 + 2 + 3 + .... 15])/15`
= `2 xx 120/15`
= 16
APPEARS IN
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 mean is one of the numbers in a data.
Solve any two of the following.
In some families in a colony the daily purchase of milk in litre is 1, 3, 2, 2, 4, 1, 2, 2, 1. Find the mean, median and mode of daily purchase of milk.
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 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.
In a week, temperature of a certain place is measured during winter are as follows 26°C, 24°C, 28°C, 31°C, 30°C, 26°C, 24°C. Find the mean temperature of the week
The mean of a set of numbers is `bar(X)`. If each number is multiplied by z, the mean is
The mean height of 11 students in a group is 150 cm. The heights of the students are 154 cm, 145 cm, Y cm, Y + 4 cm, 160 cm, 151 cm, 149 cm, 149 cm, 150 cm, 144 cm and 140 cm. Find the value of Y and the heights of two students?
The mean of the data 12, x, 28 is 18. Find the value of x
Let x, y, z be three observations. The mean of these observations is ______.
