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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 the frequency polygon representing the above data without drawing the histogram.
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उत्तर
First we obtain in the class marks (mid-marks) of the given table as:
Class-marks = `("Lower limit" + "Upper limit")/2`
Since, the new table is shown below:
| Class interval | Class marks | Frequency |
| 30 – 40 | 35 | 3 |
| 40 – 50 | 45 | 6 |
| 50 – 60 | 55 | 25 |
| 60 – 70 | 65 | 65 |
| 70 – 80 | 75 | 50 |
| 80 – 90 | 85 | 28 |
| 90 – 100 | 95 | 14 |
Now, let’s draw a frequency polygon by plotting the class marks along the x-axis and the frequency along y-axis.
Also, plotting all the points as B(35, 3), C(45, 6), (D(55, 25), E(65, 65), F(75, 50), G(85, 28) and H(95, 14).
Then join all these point line segment, shown below:

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संबंधित प्रश्न
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.
The following bar graph (Fig. 23. 1 4) represents the heights (in cm) of 50 students of Class XI of a particular school. Study the graph and answer the following questions:

(i) What percentage of the total number of students have their heights more than 149cm?
(ii) How many students in the class are in the range of maximum height of the class?
(iii) The school wants to provide a particular type of tonic to each student below the height
of 150 cm to improve his height. If the cost of the tonic for each student comes out to be Rs. 55, how much amount of money is required?
(iv) How many students are in the range of shortest height of the class?
(v) State whether true or false:
a. There are 9 students in the class whose heights are in the range of 155 - 159 cm.
b. Maximum height (in cm) of a student in the class is 17.
c. There are 29 students in the class whose heights are in the range of 145- 154 cm.
d. Minimum height (in cm) of a student is the class is in the range of 140 – 144 cms.
e. The number of students in the class having their heights less than 150 cm is 12.
f. There are 14 students each of whom has height more than 154. cm.
Read the bar graph given in Fig. 23.21 and answer the following questions:
(i) What is the information given by the bar graph?
(ii) What is the number of families having 6 members?
(iii) How many members per family are there in the maximum number of families? Also tell the number of such families.
(iv) What are the number of members per family for which the number of families are equal? Also, tell the number of such families?
Read the following bar graph and answer the following questions:
(i) What information is given by the bar graph?
(ii) In which year the export is minimum?
(iii)In which year the import is maximum?
(iv)In which year the difference of the values of export and import is maximum?

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
A frequency polygon is constructed by plotting frequency of the class interval and the
In a histogram the area of each rectangle is proportional to
In the 'less than' type of ogive the cumulative frequency is plotted against
Draw frequency polygons for each of the following frequency distribution:
(a) using histogram
(b) without using histogram
|
C.I |
5 -15 | 15 -25 | 25 -35 | 35 - 45 | 45-55 | 55-65 |
| ƒ | 8 | 16 | 18 | 14 | 8 | 2 |
Manoj appeared for ICSE examination 2018 and secured percentage of marks as shown in the following table:
| Subject | Hindi | English | Maths | Science | Social Study |
| Marks as percent | 60 | 45 | 42 | 48 | 75 |
Represent the above data by drawing a suitable bar graph.
