NCERT Solutions for Class 9 Maths Chapter 14 Statistics Ex 14.3
NCERT Solutions for Class 9 Maths Chapter 14 Statistics Ex 14.3 are the part of NCERT Solutions for Class 9 Maths. Here you can find the NCERT Solutions for Chapter 14 Statistics Ex 14.3.
Ex 14.3 Class 9 Maths Question 1.
A survey conducted by an
organisation for the cause of illness and death among the women between the
ages 15 – 44 (in years) worldwide, found the following figures (in %):
(ii) Which condition is the major cause of women’s ill health and death worldwide?
(iii) Try to find out, with the help of your teacher, any two factors which play a major role in the cause in (ii) above being the major cause.
Solution:
(i) The required graphical
representation is shown below:
(ii) The major cause of women’s ill health and death
worldwide is ‘reproductive health conditions.’
(iii) Two factors may be lack of proper diet and lack of medical facilities.
Ex 14.3 Class 9 Maths Question 2.
The following data on the number of girls (to the
nearest ten) per thousand boys in different sections of Indian society is given
below:
(i) Represent the information above by a bar graph.
(ii) In the classroom discuss, what conclusions can be arrived at from the
graph.
Solution:
(i) The required bar graph is shown below:
(ii) We conclude that number of girls per thousand
boys are maximum in scheduled tribe section whereas minimum in urban section.
Ex 14.3 Class 9 Maths Question 3.
Given below are the seats won by different political
parties in the polling outcome of a state assembly elections:
(i) Draw a bar graph to represent the polling results.
(ii) Which political party won the maximum number of seats?
Solution:
(i) The required bar graph is shown below:
(ii) The political party A won the maximum number of
seats.
Ex 14.3 Class 9 Maths Question 4.
The length of 40 leaves of a plant measured correct
to one millimetre and the obtained data is represented in the following table:
(i) Draw a histogram to represent the given data.
(ii) Is there any other suitable graphical representation for the same data?
(iii) Is it correct to conclude that the maximum number of leaves 153 mm long
and why?
Solution:
(i) The given frequency distribution table is not
continuous. Therefore, first we have to modify it to be continuous
distribution.
Thus, the modified frequency distribution table is as follows:
Now,
the required histogram of the frequency distribution is shown below:
(ii) Yes, other suitable graphical
representation is a ‘frequency polygon’.
(iii) No, it is not a correct statement. The
maximum number of leaves lie in the class interval 145 – 153.
Ex 14.3 Class 9 Maths Question 5.
The following table gives the
lifetimes of 400 neon lamps:
(ii) How many lamps have a lifetime of more than 700 hours?
Solution:
(i) The required histogram is shown
below:
(ii) The number of lamps having lifetime of more
than 700 hours = 74 + 62 + 48 = 184.
Ex 14.3 Class 9 Maths Question 6.
The following table gives the distribution of
students of two sections according to the marks obtained by them:
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.
Solution:
To draw a frequency polygon, we mark the class marks
along x-axis. Therefore, the modified table is as follows:
So, the two frequency polygons are as shown below:
From the above frequency polygon, It is clear
that from the polygon that the performance of section A is better in comparison
of section B.
Ex 14.3 Class 9 Maths Question 7.
The runs scored by two teams A and B on the first 60
balls in a cricket match are given below:
Represent the data of both the teams on the same graph by frequency polygons.
Solution:
The given class intervals are not
continuous. Therefore, we first modify the distribution as continuous.
Ex 14.3 Class 9 Maths Question 8.
A random survey of the number of children
of various age groups playing in a park was found as follows:
Solution:
Here, the class sizes are
different. So, we calculate the adjusted frequencies corresponding to each
rectangle, i.e., length of the rectangle.
Adjusted frequency or length of the rectangle
Now, the required histogram is as follows:
Ex 14.3 Class 9 Maths Question 9.
100 surnames were randomly picked up from a local
telephone directory and a frequency distribution of the number of letters in
the English alphabet in the surnames was found as follows:
(i) Draw a histogram to depict the given information.
(ii) Write the class interval in which the maximum number of surnames lie.
Solution:
(i) Since, class intervals of the
given frequency distribution are unequal, and the minimum class size = 6 – 4 =
2.
Therefore, we have the following table for
length of rectangles.
(ii)
The maximum frequency is 44, which is corresponding to the class interval 6 –
8.
∴ Maximum number of surnames lie in
the class interval 6 – 8.
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