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प्रश्न
The algebraic sum of the deviations of a frequency distribution from its mean is always ______.
विकल्प
Always positive
Always negative
Zero
A non-zero number
उत्तर
The algebraic sum of the deviations of a frequency distribution from its mean is always zero.
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संबंधित प्रश्न
The number of students absent in a class were recorded every day for 120 days and the information is given in the following frequency table:
| No. of students absent (x) | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| No. of days (f) | 1 | 4 | 10 | 50 | 34 | 15 | 4 | 2 |
Find the mean number of students absent per day.
Find the mean of each of the following frequency distributions
| Class interval | 50 - 70 | 70 - 90 | 90 - 110 | 110 - 130 | 130 - 150 | 150 - 170 |
| Frequency | 18 | 12 | 13 | 27 | 8 | 22 |
Find the mean of each of the following frequency distributions
| Class interval | 10 - 30 | 30 - 50 | 50 - 70 | 70 - 90 | 90 - 110 | 110 - 130 |
| Frequency | 5 | 8 | 12 | 20 | 3 | 2 |
Find the mean of each of the following frequency distributions
| Classes | 25 - 29 | 30 - 34 | 35 - 39 | 40 - 44 | 45 - 49 | 50 - 54 | 55 - 59 |
| Frequency | 14 | 22 | 16 | 6 | 5 | 3 | 4 |
Find the mean of the following frequency distribution table using a suitable method:
| Class | 20 – 30 | 30 – 40 | 40 – 50 | 50 – 60 | 60 - 70 |
| Frequency | 25 | 40 | 42 | 33 | 10 |
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 |
Define mean.
The following frequency distribution table shows the amount of aid given to 50 flood affected families. Find the mean of the amount of aid.
|
Amount of aid
(Thousand rupees)
|
50 - 60 | 60 - 70 | 70 - 80 | 80 - 90 | 90 - 100 |
| No. of families | 7 | 13 | 20 | 6 | 4 |
The contents of 100 match box were checked to determine the number of match sticks they contained.
| Number of match sticks | Number of boxes |
| 35 | 6 |
| 36 | 10 |
| 37 | 18 |
| 38 | 25 |
| 39 | 21 |
| 40 | 12 |
| 41 | 8 |
(i) Calculate correct to one decimal place, the mean number of match sticks per box.
(ii) Determine how many matchsticks would have to be added. To the total contents of the 100 boxes to bring the mean up exactly 39 match sticks.
Calculate the mean of the following data:
| Class | 4 – 7 | 8 – 11 | 12 – 15 | 16 – 19 |
| Frequency | 5 | 4 | 9 | 10 |
