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प्रश्न
Following table shows a frequency distribution for the speed of cars passing through at a particular spot on a high way:
| Class interval (km/h) | Frequency |
| 30 – 40 | 3 |
| 40 – 50 | 6 |
| 50 – 60 | 25 |
| 60 – 70 | 65 |
| 70 – 80 | 50 |
| 80 – 90 | 28 |
| 90 – 100 | 14 |
Draw a histogram and frequency polygon representing the data above.
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उत्तर
Clearly, the given frequency distribution is in exclusive form.
Along the horizontal axis, we represent the class intervals on some suitable scale. The corresponding frequencies are represented along the vertical axis on a suitable scale.
We construct rectangles with class intervals as the bases and the respective frequencies as the heights.
Let us draw a histogram for this data and mark the mid-points of the top of the rectangles as B, C, D, E, F, G and H, respectively. Here, the first class is 30 – 40 and the last class is 90 – 100.
Also, consider the imagined classes 20 – 30 and 100 – 110 each with frequency 0. The class marks of these classes are 25 and 105 at the points A and I, respectively.

Join all these points by dotted line.
Then, the curve ABCDEFGHI is the required frequency polygon.
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संबंधित प्रश्न
The following table gives the life times of 400 neon lamps:-
| Life time (in hours) | Number of lamps |
| 300 - 400 | 14 |
| 400 - 500 | 56 |
| 500 - 600 | 60 |
| 600 - 700 | 86 |
| 700 - 800 | 74 |
| 800 - 900 | 62 |
| 900 - 1000 | 48 |
- Represent the given information with the help of a histogram.
- How many lamps have a life time of more than 700 hours?
Read the bar graph shown in Fig. 23.10 and answer the following questions
(i) What is the information given by the bar graph?

(ii) What was the number of commercial banks in 1977?
(iii) What is the ratio of the number of commercial banks in 1969 to that in 1980?
(iv) State whether true or false:
The number of commercial banks in 1983 is less than double the number of commercial banks in 1969.
Read the bar graph given in Fig. below and answer the following questions:

(i) What information does it give?
(ii) In which part the expenditure on education is maximum in 1980?
(iii) In which part the expenditure has gone up from 1980 to 1990?
(iv) In which part the gap between 1980 and 1990 is maximum?
The production of saleable steel in some of the steel plants our country during 1999 is given below:
| Plant | Bhilai | Durgapur | Rourkela | Bokaro |
| Production (In thousand tonnes) |
160 | 80 | 200 | 150 |
Construct a bar graph to represent the above data on a graph paper by using the scale 1 big divisions = 20 thousand tonnes.
Construct a histogram for the following data:
| Monthly School fee (in Rs): |
30-60 | 60-90 | 90-120 | 120-150 | 150-180 | 180-210 | 210-240 |
| No of Schools | 5 | 12 | 14 | 18 | 10 | 9 | 4 |
The following is the distribution of total household expenditure (in Rs.) of manual worker in a city:
| Expenditure (in Rs): |
100-150 | 150-200 | 200-250 | 250-300 | 300-350 | 350-400 | 400-450 | 450-500 |
| No. of manual workers: | 25 | 40 | 33 | 28 | 30 | 22 | 16 | 8 |
Draw a histogram and a frequency polygon representing the above data.
The following table gives the distribution of IQ's (intelligence quotients) of 60 pupils of class V in a school:
| IQ's: | 125.5 to 13.25 |
118.5 to 125.5 |
111.5 to 118.5 |
104.5 to 111.5 |
97.5 to 104.5 |
90.5 to 97.5 |
83.5 to 90.5 |
76.5 to 83.5 |
69.5 to 76.5 |
62.5 to 69.5 |
| No. of pupils: |
1 | 3 | 4 | 6 | 10 | 12 | 15 | 5 | 3 | 1 |
Draw a frequency polygon for the above data.
Students of a small school use different modes of travel to school as shown below:
| Mode | Bus | Car | Bicycle | Auto | On foot |
| No. of students | 142 | 98 | 50 | 34 | 16 |
Draw a suitable bar graph.
The following table gives the frequencies of most commonly used letters a, e, i, o, r, t, u from a page of a book:
| Letters | a | e | i | o | r | t | u |
| Frequency | 75 | 125 | 80 | 70 | 80 | 95 | 75 |
Represent the information above by a bar graph.
Draw a histogram to represent the following grouped frequency distribution:
| Ages (in years) | Number of teachers |
| 20 – 24 | 10 |
| 25 – 29 | 28 |
| 30 – 34 | 32 |
| 35 – 39 | 48 |
| 40 – 44 | 50 |
| 45 – 49 | 35 |
| 50 – 54 | 12 |
