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प्रश्न
Construct a frequency polygon without using a histogram for the following frequency distribution :
| Class Interval | 10-20 | 20-40 | 40-60 | 60-80 | 80-100 |
| Frequency | 9 | 17 | 15 | 20 | 14 |
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उत्तर
Steps :
1. Find class mark by calculating the average of the class interval.
2. On the x-axis , take 1 cm as 5 units and plot class interval.
3. On the y-axis , take 1 cm as 5 units and plot frequency.
4. plot the points on the graph. (15,9),(30,17),(50,15),(70,20),(90,14).
5. Mark two more midpoints of zero frequency on x-axis at the start and at the end .
6. Now connect the points using staright lines.
| Class Interval | Class mark | Frequency |
| 10-20 | `= (10+20)/2 = 15` | 9 |
| 20-40 | `= (20+40)/2 = 30` | 17 |
| 40-60 | `= (40+60)/2 = 50` | 15 |
| 60-80 | `= (60 + 80)/2 = 70` | 20 |
| 80-100 | `= (80 + 100)/2 = 90` | 14 |
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संबंधित प्रश्न
Given below is the frequency distribution of driving speeds (in km/hour) of the vehicles of 400 college students:
| Speed (in km/hr) | No. of Students |
| 20-30 | 6 |
| 30-40 | 80 |
| 40-50 | 156 |
| 50-60 | 98 |
60-70 |
60 |
Draw Histogram and hence the frequency polygon for the above data.
The number of hours for which students of a particular class watched television during holidays is shown through the given graph.
Answer the following
1) For how many hours did the maximum number of students watch TV?
2) How many students watched TV for less than 4 hours?
3) How many students spent more than 5 hours in watching TV?
| Result (Percentage) | 30 - 40 | 40 - 50 | 50 - 60 | 60 -70 | 70 - 80 | 80 - 90 | 90 - 100 |
| No. of students | 7 | 33 | 45 | 65 | 47 | 18 | 5 |
The following table shows the investment made by some families. Show
the information by a histogran.
| Investment (Thousand Rupees) |
10-15 | 15-20 | 20-25 | 25-30 | 30-35 |
| No. of families | 30 | 50 | 60 | 55 | 15 |
The following frequency distribution table shows marks obtained by 180 students in Mathematics examination.
| Marks | No. of students |
| 0 - 10 | 25 |
| 10 - 20 | x |
| 20 - 30 | 30 |
| 30 - 40 | 2x |
| 40 - 50 | 65 |
Find the value of x. Also draw a histogram representing the above information.
Construct histograms for following frequency distribution:
| Class Interval | 110-119 | 120-129 | 130-139 | 140-149 | 150-159 |
| Frequency | 15 | 23 | 30 | 20 | 16 |
Construct a frequency polygon without using a histogram for the following frequency distribution :
| Class Interval | 1-10 | 11-20 | 21-30 | 31-40 | 41-50 |
| Frequency | 8 | 12 | 10 | 16 | 6 |
Draw the Histogram and hence, the frequency polygon for the following frequency distribution:
| House Rent (In ₹ per month) | 400-600 | 600-800 | 800-1000 | 1000-1200 |
| Number of families | 200 | 240 | 300 | 50 |
Form a continuous frequency distribution table and draw histogram from the following data.
| Age (in years) | No. of persons |
| Under 5 | 1 |
| Under 10 | 12 |
| Under 15 | 19 |
| Under 20 | 26 |
| Under 25 | 27 |
| Under 30 | 35 |
| Under 35 | 38 |
| Under 40 | 45 |
| Under 45 | 48 |
| Under 50 | 53 |
Try yourself
- Next time when you watch your favourite TV programme, count the number of advertisements during each break. Use tally marks. Put a dot below the tally when you find children in any advertisement.
- Compare with your friends. Do you get different answers?
