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प्रश्न
The marks obtained by 100 students of a class in an examination are given below.
| Marks | No. of students |
| 0-5 | 2 |
| 5-10 | 5 |
| 10-15 | 6 |
| 15-20 | 8 |
| 20-25 | 10 |
| 25-30 | 25 |
| 30-35 | 20 |
| 35-40 | 18 |
| 40-45 | 4 |
| 45-50 | 2 |
Draw 'a less than' type cumulative frequency curves (orgive). Hence find median
उत्तर
| Marks | No. of students | Marks less than | Cumulative frequency |
| 0-5 | 2 | Less than 5 | 2 |
| 5-10 | 5 | Less than 10 | 7 |
| 10-15 | 6 | Less than 15 | 13 |
| 15-20 | 8 | Less than 20 | 21 |
| 20-25 | 10 | Less than 25 | 31 |
| 25-30 | 25 | Less than 30 | 56 |
| 30-35 | 20 | Less than 35 | 76 |
| 35-40 | 18 | Less than 40 | 94 |
| 40-45 | 4 | Less than 45 | 98 |
| 45-50 | 2 | Less than 50 | 100 |
Let us now plot the points corresponding to the ordered pairs (5, 2), (10, 7) (15,13), (20, 21), (25,31), (30,56), (35,76), (40,94), (45,98), (50,100). Join all the points by a smooth curve.
Locate `"n"/2 = 100/2 = 50` on Y-axis
From this point draw a line parallel to X-axis cutting the curve at a point. From this point, draw a perpendicular to X-axis. The point of intersection of perpendicular with the X-axis determines the median of the data. Therefore median = 28.8
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संबंधित प्रश्न
Draw an ogive by less than method for the following data:
| No. of rooms: | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| No. of houses: | 4 | 9 | 22 | 28 | 24 | 12 | 8 | 6 | 5 | 2 |
The marks scored by 750 students in an examination are given in the form of a frequency distribution table:
| Marks | No. of students |
| 600 - 640 | 16 |
| 640 - 680 | 45 |
| 680 - 720 | 156 |
| 720 - 760 | 284 |
| 760 - 800 | 172 |
| 800 - 840 | 59 |
| 840 - 880 | 18 |
Draw a cumulative frequency curve (ogive) for the following distributions:
| Class Interval | 10 – 19 | 20 – 29 | 30 – 39 | 40 – 49 | 50 – 59 |
| Frequency | 23 | 16 | 15 | 20 | 12 |
Draw an ogive for the following distributions:
| Marks obtained | less than 10 | less than 20 | less than 30 | less than 40 | less than 50 |
| No. of students | 8 | 25 | 38 | 50 | 67 |
Find the correct answer from the alternatives given.
Cumulative frequencies in a grouped frequency table are useful to find ______.
Draw an ogive for the following :
| Class Interval | 100-150 | 150-200 | 200-250 | 250-300 | 300-350 | 350-400 |
| Frequency | 10 | 13 | 17 | 12 | 10 | 8 |
Find the width of class 35 - 45.
Prepare the cumulative frequency (less than types) table from the following distribution table :
| Class | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
| Frequency | 2 | 3 | 7 | 8 | 5 |
The following is the frequency distribution with unknown frequencies :
| Class | 60-70 | 70-80 | 80-90 | 90-100 | Total |
| frequency | `"a"/2` | `(3"a")/2` | 2a | a | 50 |
Find the value of a, hence find the frequencies. Draw a histogram and frequency polygon on the same coordinate system.
Using a graph paper, drawn an Ogive for the following distribution which shows a record of the weight in kilograms of 200 students.
| Weight | Frequency |
| 40 - 45 | 5 |
| 45 - 50 | 17 |
| 50 - 55 | 22 |
| 55 - 60 | 45 |
| 60 - 65 | 51 |
| 65 - 70 | 31 |
| 70 - 75 | 20 |
| 75 - 80 | 9 |
Use your ogive to estimate the following:
(i) The percentage of students weighing 55kg or more.
(ii) The weight above which the heaviest 30% of the students fall.
(iii) The number of students who are:
(1) under-weight and
(2) over-weight, if 55·70 kg is considered as standard weight.
