Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
| Electricity used (units) `bb(x_i)` |
No. of Families (frequency) `bb(f_i)` |
`bb(f_ix_i)` |
| 30 | 7 | 30 × 7 = 210 |
| 45 | 2 | 45 × 2 = 90 |
| 60 | 8 | 60 × 8 = 480 |
| 75 | 5 | 75 × 5 = 375 |
| 90 | 3 | 90 × 3 = 270 |
| N = 25 | `sum f_ix_i` = 1425 |
(1) 2 families use 45 units of electricity.
(2) The score with a frequency of 5 is 75 units.
(3) N = 25, and `sum f_ix_i`= 1425
(4) Since,
= `1425/25`
= 57
So, the mean of electricity used by each family in the month of May is 57.
संबंधित प्रश्न
The mean is one of the numbers in a data.
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` "n"^(th)` term of the A. P. 3, 8, 13, 18, ............ is 148. Find n
The calculated mean of 50 observations was 80. It was later discovered that observation 19 was recorded by mistake as 91. What was the correct mean?
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
In a class test in mathematics, 10 students scored 75 marks, 12 students scored 60 marks, 8 students scored 40 marks and 3 students scored 30 marks. Find the mean of their score
The mean of a, b, c, d and e is 28. If the mean of a, c and e is 24, then mean of b and d is
The mean of 5, 9, x, 17 and 21 is 13, then find the value of x
The marks of 14 students in a science test out of 50 are given below. 34, 23, 10, 45, 44, 47, 35, 37, 41, 30, 28, 32, 45, 39 Find the mean mark
Mean of the observations can be lesser than each of the observations.
