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Question
| Electricity bill (₹) | 0 - 200 | 200 - 400 | 400 - 600 | 600 - 800 | 800 - 1000 |
| Families | 240 | 300 | 450 | 350 | 160 |
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Solution
Consider the following table.
| Class (Electricity bill in Rupees) |
Class Mark | Frequency (Number of families) |
| 0 - 200 | 100 | 240 |
| 200 - 400 | 300 | 300 |
| 400 - 600 | 500 | 450 |
| 600 - 800 | 700 | 350 |
| 800 - 1000 | 900 | 160 |
The frequency polygon using the class mark and frequency given in the above table as
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RELATED QUESTIONS
For which of these would you use a histogram to show the data?
(a) The number of letters for different areas in a postman’s bag.
(b) The height of competitors in an athletics meet.
(c) The number of cassettes produced by 5 companies.
(d) The number of passengers boarding trains from 7:00 a.m. to 7:00 p.m. at a station.
Give reasons for each.
Draw histogram and frequency polygon on the same graph paper for the following frequency distribution
| Class | Frequency |
| 15-20 | 20 |
| 20-25 | 30 |
| 25-30 | 50 |
| 30-35 | 40 |
| 35-40 | 25 |
| 40-45 | 10 |
A Mathematics aptitude test of 50 students was recorded as follows:
| Marks | 50 - 60 | 60 - 70 | 70 - 80 | 80 - 90 | 90 – 100 |
| No. of Students | 4 | 8 | 14 | 19 | 5 |
Draw a histogram from the above data using a graph paper and locate the mode.
Draw histogram for the following frequency distributions:
| Class Marks | 16 | 24 | 32 | 40 | 48 | 56 | 64 |
| Frequency | 8 | 12 | 15 | 18 | 25 | 19 | 10 |
Observe the following frequency polygon and write the answers of the questions below it.
- Which class has the maximum number of students?
- Write the classes having zero frequency.
- What is the class-mark of the class, having frequency of 50 students?
- Write the lower and upper class limits of the class whose class mark is 85.
- How many students are in the class 80-90?
| 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 |
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 |
The marks scored by students in Mathematics in a certain examination are given below :
| Marks Scored | Number of Students |
| 0 - 20 | 6 |
| 20 - 40 | 9 |
| 40 - 60 | 14 |
| 60 - 80 | 16 |
| 80 - 100 | 5 |
Draw histogram for the above data.
The time taken, in seconds, to solve a problem for each of 25 persons is as follows:
| 16 | 20 | 26 | 27 | 28 |
| 30 | 33 | 37 | 38 | 40 |
| 42 | 43 | 46 | 46 | 47 |
| 48 | 49 | 50 | 53 | 58 |
| 59 | 60 | 64 | 52 | 20 |
(i) Construct a frequency distribution for these data using a class interval of 10 seconds.
(ii) In a school the weekly pocket money of 50 students is as follow's:
| Weekly pocket money (₹) | No. of student |
| 40 - 50 | 2 |
| 59 - 60 | 8 |
| 60 - 70 | 12 |
| 70 - 80 | 14 |
| 80 - 90 | 8 |
| 90 - 100 | 6 |
Draw a histogram and a frequency polygon on the same graph. Find mode from the graph.
(Use a graph paper for this question.) The daily pocket expenses of 200 students in a school are given below:
| Pocket expenses (in ₹) |
Number of students (frequency) |
| 0 - 5 | 10 |
| 5 - 10 | 14 |
| 10 - 15 | 28 |
| 15 - 20 | 42 |
| 20 - 25 | 50 |
| 25 - 30 | 30 |
| 30 - 35 | 14 |
| 35 - 40 | 12 |
Draw a histogram representing the above distribution and estimate the mode from the graph.
Identify the following data can be represented in a histogram?
Production of cycles in different years
Histogram is a graph of a ________ frequency distribution
The graphical representation of grouped data is _________
Draw a histogram for the given frequency distribution
| Age | 41 − 45 | 46 − 50 | 51 − 55 | 56 − 60 | 61 − 65 | 66 − 70 | 71 − 75 |
| Frequency | 4 | 9 | 17 | 25 | 15 | 8 | 2 |
Draw a histogram and the frequency polygon in the same diagram to represent the following data
| Weight (in kg) | 50 − 55 | 56 − 61 | 62 − 67 | 68 − 73 | 74 − 79 | 80 − 85 | 86 − 91 |
| No. of persons | 15 | 8 | 12 | 17 | 9 | 10 | 6 |
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?
Prepare a histogram from the frequency distribution table obtained in question 93.
The following histogram shows the frequency distribution of teaching experiences of 30 teachers in various schools:
- What is the class width?
- How many teachers are having the maximum teaching experience and how many have the least teaching experience?
- How many teachers have teaching experience of 10 to 20 years?
The table given below shows the runs scored by a cricket team during the overs of a match.
| Overs | Runs scored |
| 20 – 30 | 37 |
| 30 – 40 | 45 |
| 40 – 50 | 40 |
| 50 – 60 | 60 |
| 60 – 70 | 51 |
| 70 – 80 | 35 |
Use graph sheet for this question.
Take 2 cm = 10 overs along one axis and 2 cm = 10 runs along the other axis.
- Draw a histogram representing the above distribution.
- Estimate the modal runs scored.
