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Question
Construct a frequency distribution table for the following distributions:
| Marks (less than) | 0 | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
| Cumulative frequency | 0 | 7 | 28 | 54 | 71 | 84 | 105 | 147 | 180 | 196 | 200 |
Solution
| Marks (less than) |
Cumulative frequency |
Frequency |
| 0-10 | 7 | 7 |
| 10-20 | 28 | 28 - 7 = 21 |
| 20-30 | 54 | 54 - 28 = 26 |
| 30-40 | 71 | 71 - 54 = 17 |
| 40-50 | 84 | 84 - 71 = 13 |
| 50-60 | 105 | 105 - 84 = 21 |
| 60-70 | 147 | 147 - 105 = 42 |
| 70-80 | 180 | 180 - 147 = 33 |
| 80-90 | 196 | 196 - 180 = 16 |
| 90-100 | 200 | 200 - 196 = 4 |
| Total | 200 |
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RELATED QUESTIONS
Draw a cumulative frequency curve (ogive) for the following distributions:
| Class Interval | 10 – 15 | 15 – 20 | 20 – 25 | 25 – 30 | 30 – 35 | 35 – 40 |
| Frequency | 10 | 15 | 17 | 12 | 10 | 8 |
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 :
| Class Interval | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
| Frequency | 8 | 12 | 10 | 14 | 6 |
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 |
Draw an ogive for the following :
| Marks obtained | Less than 10 | Less than 20 | Less than 30 | Less than 40 | Less than 50 |
| No. of students | 8 | 22 | 48 | 60 | 75 |
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
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.
The frequency distribution of scores obtained by 230 candidates in a medical entrance test is as ahead:
| Cost of living Index | Number of Months |
| 400 - 450 | 20 |
| 450 - 500 | 35 |
| 500 - 550 | 40 |
| 550 - 600 | 32 |
| 600 - 650 | 24 |
| 650 - 700 | 27 |
| 700 - 750 | 18 |
| 750 - 800 | 34 |
| Total | 230 |
Draw a cummulative polygon (ogive) to represent the above data.
Use graph paper for this question. The following table shows the weights in gm of a sample of 100 potatoes taken from a large consignment:
| Weight (gms) | Frequency |
| 50 - 60 | 8 |
| 60 - 70 | 10 |
| 70 - 80 | 12 |
| 80 - 90 | 16 |
| 90 - 100 | 18 |
| 100 - 110 | 14 |
| 110 - 120 | 12 |
| 120 - 130 | 10 |
(i) Calculate the cumulative frequencies.
(ii) Draw the cumulative frequency curve and form it determine the median weights of the potatoes.
