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प्रश्न
Write the median class of the following distribution:
| Class | 0 – 10 | 10 -20 | 20- 30 | 30- 40 | 40-50 | 50- 60 | 60- 70 |
| Frequency | 4 | 4 | 8 | 10 | 12 | 8 | 4 |
उत्तर
To find median let us put the data in the table given below:
| Class | Frequency` (f_i)` | Cumulative frequency (cf) |
| 0-10 | 4 | 4 |
| 10-20 | 4 | 8 |
| 20-30 | 8 | 16 |
| 30-40 | 10 | 26 |
| 40-50 | 12 | 38 |
| 50-60 | 8 | 46 |
| 60-70 | 4 | 50 |
| Total | `N=Σf_i=50` |
Now, `N=50⟹N/2=25`
The cumulative frequency just greater than 25 is 26, and the corresponding class is 30-40.
Thus, the median class is 30-40.
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संबंधित प्रश्न
Draw a ‘more than’ ogive for the data given below which gives the marks of 100 students.
| Marks | 0 – 10 | 10 – 20 | 20 – 30 | 30 - 40 | 40 – 50 | 50 – 60 | 60 – 70 | 70 – 80 |
| No of Students | 4 | 6 | 10 | 10 | 25 | 22 | 18 | 5 |
What is the lower limit of the modal class of the following frequency distribution?
| Age (in years) | 0 - 10 | 10- 20 | 20 -30 | 30 – 40 | 40 –50 | 50 – 60 |
| Number of patients | 16 | 13 | 6 | 11 | 27 | 18 |
The following table gives the life-time (in days) of 100 electric bulbs of a certain brand.
| Life-tine (in days) | Less than 50 |
Less than 100 |
Less than 150 |
Less than 200 |
Less than 250 |
Less than 300 |
| Number of Bulbs | 7 | 21 | 52 | 9 | 91 | 100 |
The median of the distribution given below is 14.4 . Find the values of x and y , if the total frequency is 20.
| Class interval : | 0-6 | 6-12 | 12-18 | 18-24 | 24-30 |
| Frequency : | 4 | x | 5 | y | 1 |
The mode of a frequency distribution can be determined graphically from ______.
The mean of a discrete frequency distribution xi / fi, i = 1, 2, ......, n is given by
If the median of the following frequency distribution is 32.5. Find the values of f1 and f2.
Calculate the mean of the following frequency distribution :
| Class: | 10-30 | 30-50 | 50-70 | 70-90 | 90-110 | 110-130 |
| Frequency: | 5 | 8 | 12 | 20 | 3 | 2 |
Form the frequency distribution table from the following data:
| Marks (out of 90) | Number of candidates |
| More than or equal to 80 | 4 |
| More than or equal to 70 | 6 |
| More than or equal to 60 | 11 |
| More than or equal to 50 | 17 |
| More than or equal to 40 | 23 |
| More than or equal to 30 | 27 |
| More than or equal to 20 | 30 |
| More than or equal to 10 | 32 |
| More than or equal to 0 | 34 |
Find the unknown entries a, b, c, d, e, f in the following distribution of heights of students in a class:
| Height (in cm) |
Frequency | Cumulative frequency |
| 150 – 155 | 12 | a |
| 155 – 160 | b | 25 |
| 160 – 165 | 10 | c |
| 165 – 170 | d | 43 |
| 170 – 175 | e | 48 |
| 175 – 180 | 2 | f |
| Total | 50 |
