Advertisements
Advertisements
प्रश्न
Calculate the mean of the following data:
| Class | 4 – 7 | 8 – 11 | 12 – 15 | 16 – 19 |
| Frequency | 5 | 4 | 9 | 10 |
उत्तर
Since, given data is not continuous, so we subtract 0.5 from the lower limit and add 0.5 in the upper limit of each class.
Now, we first find the class mark xi of each class and then proceed as follows.
| Class | Class marks `(bb(x_i))` |
Frequency `(bb(f_i))` |
`bb(f_ix_i)` |
| 3.5 – 7.5 | 5.5 | 5 | 27.5 |
| 7.5 – 11.5 | 9.5 | 4 | 38 |
| 11.5 – 15.5 | 13.5 | 9 | 121.5 |
| 15.5 – 19.5 | 17.5 | 10 | 175 |
| `sumf_i = 28` | `sumf_ix_i = 362` |
Therefore, mean `(barx) = (sumf_ix_i)/(sumf_i)`
= `362/28`
= 12.93
Hence, mean of the given data is 12.93.
APPEARS IN
संबंधित प्रश्न
The following table gives the frequency distribution of trees planted by different Housing Societies in a particular locality:
| No. of Trees | No. of Housing Societies |
| 10-15 | 2 |
| 15-20 | 7 |
| 20-25 | 9 |
| 25-30 | 8 |
| 30-35 | 6 |
| 35-40 | 4 |
Find the mean number of trees planted by Housing Societies by using ‘Assumed Means Method’
The following distribution shows the daily pocket allowance of children of a locality. The mean pocket allowance is Rs.18. Find the missing frequency f.
| Daily pocket allowance (in Rs | 11 - 13 | 13 - 15 | 15 - 17 | 17 - 19 | 19 - 21 | 21 - 23 | 23 - 25 |
| Number of workers | 7 | 6 | 9 | 13 | f | 5 | 4 |
Find the mean of the following data:-
| x | 19 | 21 | 23 | 25 | 27 | 29 | 31 |
| f | 13 | 15 | 16 | 18 | 16 | 15 | 13 |
If the mean of the following distribution is 27, find the value of p.
| Class | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 |
| Frequency | 8 | p | 12 | 13 | 10 |
Find the mean of the following frequency distribution is 57.6 and the total number of observation is 50.
| Class | 0-20 | 20-40 | 40-60 | 60-80 | 80-100 | 100-120 |
| Frequency | 7 | `f_1` | 12 | `f_2` | 8 | 5 |
The following table gives the literacy rate (in percentage) in 40 cities. Find the mean literacy rate, choosing a suitable method .
| Literacy rate(%) |
45 – 55 | 55 – 65 | 65 – 75 | 75 – 85 | 85 – 95 |
| Number of cities |
4 | 11 | 12 | 9 | 4 |
Find the mean of the following data using step-deviation method:
| Class | 500 – 520 | 520 – 540 | 540 – 560 | 560 – 580 | 580 – 600 | 600 – 620 |
| Frequency | 14 | 9 | 5 | 4 | 3 | 5 |
The following table shows the income of farmers in a grape season. Find the mean of their income.
|
Income
(Thousand Rupees)
|
20 - 30 | 30 - 40 | 40 - 50 | 50 - 60 | 60 - 70 | 70 - 80 |
| Farmers | 10 | 11 | 15 | 16 | 18 | 14 |
The loans sanctioned by a bank for construction of farm ponds are shown in the following table. Find the mean of the loans.
|
Loan
(Thousand Rupees)
|
40 - 50 | 50 - 60 | 60 - 70 | 70 - 80 | 80 - 90 |
| No. of farm ponds | 13 | 20 | 24 | 36 | 7 |
An aircraft has 120 passenger seats. The number of seats occupied during 100 flights is given in the following table:
| Number of seats | 100 – 104 | 104 – 108 | 108 – 112 | 112 – 116 | 116 – 120 |
| Frequency | 15 | 20 | 32 | 18 | 15 |
