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प्रश्न
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.
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उत्तर
In case of the data given in alternative (b) and (d), we will use histogram as we can divide the given data in class intervals. In case of alternatives (a) and (c), we do not know about the number of letters of different areas and the number of cassettes produced by the given companies. We do not have any approximate idea about it. Therefore, we cannot define class intervals for this data and thus, we will not use a histogram.
संबंधित प्रश्न
The marks scored by students in Mathematics in a certain Examination are given below:
| Marks Scored | Number of Students |
| 0 — 20 | 3 |
| 20 — 40 | 8 |
| 40 — 60 | 19 |
| 60 — 80 | 18 |
| 80 — 100 | 6 |
Draw histogram for the above data.
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.
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 |
Time alloted for the preparation of an examination by some students is shown in the table. Draw a histogram to show the information.
| Time (minutes) | 60 - 80 | 80 - 100 | 100 - 120 | 120 - 140 | 140 - 160 |
| No. of students | 14 | 20 | 24 | 22 | 16 |
The age groups and the number of persons in the age groups, who donated blood in blood donation camp is given below. Find the measures of central angles to show the information by a pie diagram.
| Age group (Years) | 20-25 | 25-30 | 30-35 | 35-40 |
| No of persons | 80 | 60 | 35 | 25 |
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 histogram shows the number of literate females in the age group of 10 to 40 years in a town:
(i) Write the age group in which the number of literate female is the highest.
(ii) What is the class width?
(iii) What is the lowest frequency?
(iv) What are the class marks of the classes?
(v) In which age group literate females are the least?
The following histogram shows the frequency distribution f the ages of 22 teachers in a school:
(i) What is the number of eldest and youngest teachers in the school?
(ii) Which age group teachers are more in the school and which least?
(iii) What is the size of the classes?
(iv) What are the class marks of the classes?
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 |
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.
A graph that displays data that changes continuously over the periods of time is _________
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?
The height of a rectangle in a histogram shows the ______.
In a histogram ______ are drawn with width equal to a class interval without leaving any gap in between.
The top speeds of thirty different land animals have been organised into a frequency table. Draw a histogram for the given data.
| Maximum Speed (km/h) | Frequency |
| 10 – 20 | 5 |
| 20 – 30 | 5 |
| 30 – 40 | 10 |
| 40 – 50 | 8 |
| 50 – 60 | 0 |
| 60 – 70 | 2 |
Look at the histogram below and answer the questions that follow.
- How many students have height more than or equal to 135 cm but less than 150 cm?
- Which class interval has the least number of students?
- What is the class size?
- How many students have height less than 140 cm?
Prepare a histogram from the frequency distribution table obtained in question 93.
