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Question
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.
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Solution
The cummulative frequency table for the given frequency table as given below:
| Interval (Score) |
Frequency | Cummulative Frequency |
| 400 - 450 | 20 | 20 |
| 450 - 500 | 35 | 55 |
| 500 - 550 | 40 | 95 |
| 550 - 600 | 32 | 127 |
| 600 - 650 | 24 | 151 |
| 650 - 700 | 27 | 178 |
| 700 - 750 | 18 | 196 |
| 750 - 800 | 34 | 230 |
Ogive representing the scores obtained by 230 candidates in a medical entrance test.
RELATED QUESTIONS
The daily wages of 80 workers in a project are given below.
| Wages (in Rs.) |
400-450 | 450-500 | 500-550 | 550-600 | 600-650 | 650-700 | 700-750 |
| No. of workers |
2 | 6 | 12 | 18 | 24 | 13 | 5 |
Use a graph paper to draw an ogive for the above distribution. (Use a scale of 2 cm = Rs. 50 on x-axis and 2 cm = 10 workers on y-axis). Use your ogive to estimate:
- the median wage of the workers.
- the lower quartile wage of workers.
- the numbers of workers who earn more than Rs. 625 daily.
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:
| Age in years (less than) | 10 | 20 | 30 | 40 | 50 | 60 | 70 |
| Cumulative frequency | 0 | 17 | 32 | 37 | 53 | 58 | 65 |
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 |
Draw an ogive for the following :
| Age in years | Less than 10 | Less than 20 | Less than 30 | Less than 40 | Less than 50 |
| No. of people | 0 | 17 | 42 | 67 | 100 |
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
Find the width of class 35 - 45.
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.
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.
