Advertisements
Advertisements
Question
The runs scored by two teams A and B on the first 60 balls in a cricket match are given below:
| Number of balls | Team A | Team B |
| 1 - 6 | 2 | 5 |
| 7 - 12 | 1 | 6 |
| 13 - 18 | 8 | 2 |
| 19 - 24 | 9 | 10 |
| 25 - 30 | 4 | 5 |
| 31 - 36 | 5 | 6 |
| 37 - 42 | 6 | 3 |
| 43 - 48 | 10 | 4 |
| 49 - 54 | 6 | 8 |
| 55 - 60 | 2 | 10 |
Represent the data of both the teams on the same graph by frequency polygons.
[Hint: First make the class intervals continuous.]
Advertisements
Solution
It can be observed that the class intervals of the given data are not continuous. There is a gap of 1 between them. Therefore, `1/2` = 0.5 has to be added to the upper class limits and 0.5 has to be subtracted from the lower class limits.
Also, the class mark of each interval can be found by using the following formula.
Classmark = `"Upper class limit + Lower class limit"/2`
Continuous data with the class mark of each class interval can be represented as follows:
| Number of balls | Classmark | Team A | Team B |
| 0.5 − 6.5 | 3.5 | 2 | 5 |
| 6.5 − 12.5 | 9.5 | 1 | 6 |
| 12.5 − 18.5 | 15.5 | 8 | 2 |
| 18.5 − 24.5 | 21.5 | 9 | 10 |
| 24.5 − 30.5 | 27.5 | 4 | 5 |
| 30.5 − 36.5 | 33.5 | 5 | 6 |
| 36.5 − 42.5 | 39.5 | 6 | 3 |
| 42.5 − 48.5 | 45.5 | 10 | 4 |
| 48.5 − 54.5 | 51.5 | 6 | 8 |
| 54.5 − 60.5 | 57.5 | 2 | 10 |
By taking class marks on the x-axis and runs scored on the y-axis, a frequency polygon can be constructed as follows:

APPEARS IN
RELATED QUESTIONS
Study the bar graph representing the number of persons in various age groups in a town shown in Fig. below. Observe the bar graph and answer the following questions:
(i) What is the percentage of the youngest age-group persons over those in the oldest age group?
(ii) What is the total population of the town?
(iii) What is the number of persons in the age group 60 - 65?
(iv) How many persons are more in the age-group 10 - 15 than in the age group 30 - 35?
(v) What is the age-group of exactly 1200 persons living in the town?
(vi) What is the total number of persons living in the town in the age-group 50 - 55?
(vii) What is the total number of persons living in the town in the age-groups 10 - 15 and 60 - 65?

(viii) Whether the population in general increases, decreases or remains constant with the increase in the age-group.
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. 23.20 and answer the fol1owing questions:

(i) What information is given by the bar graph?
(ii) What was the expenditure on health and family planning in the year 1982-83?
(iii) In which year is the increase in expenditure maximum over the expenditure in previous year? What is the maximum increase?
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
The following table shows the number of Maruti cars sold by five dealers in a particular month:
| Dealer: | Saya | Bagga Links | D.D. Motors | Bhasin Motors | Competent |
| Cars sold: | 60 | 40 | 20 | 15 | 10 |
Represent the above information by a pictograph.
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.
The following data shows the average age of men in various countries in a certain year:
| Country | India | Nepal | China | Pakistan | U.K | U.S.A |
| Average age (in years) |
55 | 52 | 60 | 50 | 70 | 75 |
Represent the above information by a bar graph.
A frequency polygon is constructed by plotting frequency of the class interval and the
Mr. Mirza’s monthly income is Rs. 7,200. He spends Rs. 1,800 on rent, Rs. 2,700 on food, Rs. 900 on the education of his children; Rs. 1,200 on Other things and saves the rest.
Draw a pie-chart to represent it.
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 |
