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प्रश्न
Explain the reading and interpretation of bar graphs.
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उत्तर १
First step in reading a bar graph is to know what it represents or what is the information given by it, for this we read the captions. Which are generally written just below the horizontal line ( x- axis) and adjacent to vertical line (y - axis )
After knowing that what a bar graph represents, we read the scale so that we can know the precise value in the given data.
After reading a bar graph one must be able to draw certain condusions from it. Drawing some conditions from a given bar graph means interpretation of the bar grph.
उत्तर २
A bar graph is a diagram consisting of a sequence of vertical or horizontal bars or rectangles, each of which represents an equal interval of the values of a variable, and has height proportional to the quantities of the phenomenon under consideration in that interval. A bar graph may also be used to illustrate discrete data, in which case each bar represents a distinct circumstance.
While drawing a bar graph, we keep in mind that
1. The width of the bars should be uniform throughout.
2. The gap between any two bars should be uniform throughout.
3. Bars may be either horizontal or vertical.
Each bar must be of same width and the gap between them must be uniform. Make sure that the width of the bars and the gap between them should not be necessarily same.
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संबंधित प्रश्न
The length of 40 leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table:-
| Length (in mm) | Number of leaves |
| 118 - 126 | 3 |
| 127 - 135 | 5 |
| 136 - 144 | 9 |
| 145 - 153 | 12 |
| 154 - 162 | 5 |
| 163 - 171 | 4 |
| 172 - 180 | 2 |
- Draw a histogram to represent the given data. [Hint: First make the class intervals continuous]
- Is there any other suitable graphical representation for the same data?
- Is it correct to conclude that the maximum number of leaves are 153 mm long? Why?
The following table gives the distribution of students of two sections according to the mark obtained by them:-
| Section A | Section B | ||
| Marks | Frequency | Marks | Frequency |
| 0 - 10 | 3 | 0 - 10 | 5 |
| 10 - 20 | 9 | 10 - 20 | 19 |
| 20 - 30 | 17 | 20 - 30 | 15 |
| 30 - 40 | 12 | 30 - 40 | 10 |
| 40 - 50 | 9 | 40 - 50 | 1 |
Represent the marks of the students of both the sections on the same graph by two frequency polygons. From the two polygons compare the performance of the two sections.
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.
The bar graph shown in Fig 23.16 represents the circulation of newspapers in 10 languages. Study the bar graph and answer the following questions:

(i) What is the total number of newspapers published in Hindi, English, Urdu, Punjabi and Bengali?
(ii) What percent is the number of news papers published in Hindi of the total number of newspapers?
(iii) Find the excess of the number of newspapers published in English over those published in Urdu.
(iv) Name two pairs of languages which publish the same number of newspapers.
(v) State the language in which the smallest number of newspapers are published.
(vi) State the language in which the largest number of newspapers are published.
(vii) State the language in which the number of newspapers published is between 2500 and 3500.
(viii) State whether true or false:
a. The number of newspapers published in Malayalam and Marathi together is less than those published in English.
b. The number of newspapers published in Telugu is more than those published in Tamil.
The following bar graph shows the results of an annual examination in a secondary school. Read the bar graph and choose the correct alternative in each of the following:

(i) The pair of classes in which the results of boys and girls are inversely proportional are:
(a) VI, VIII (b) VI, IX (c) VIII, IX (d) VIII, X
(ii) The class having the lowest failure rate of girls is
(a) VII (b) X (c) IX (d) VIII
(iii)The class having the lowest pass rate of students is
(a) VI (b) VII (c) VIII (d) IX
In a histogram, each class rectangle is constructed with base as
The percentage of marks obtained, in different subjects by Ashok Sharma (in an examination) is given below. Draw a bar graph to represent it.
| English | Hindi | Maths | Science | Social Studies |
| 85 | 60 | 35 | 50 | 70 |
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.
In a diagnostic test in mathematics given to students, the following marks (out of 100) are recorded:
46, 52, 48, 11, 41, 62, 54, 53, 96, 40, 98, 44
Which ‘average’ will be a good representative of the above data and why?
The marks obtained (out of 100) by a class of 80 students are given below:
| Marks | Number of students |
| 10 – 20 | 6 |
| 20 – 30 | 17 |
| 30 – 50 | 15 |
| 50 – 70 | 16 |
| 70 – 100 | 26 |
Construct a histogram to represent the data above.
