FRANK Solutions for Class 9 Maths Chapter 22  Statistics
Chapter 22  Statistics Exercise Ex. 22.1
Question 1
Solution 1
Question 2
Solution 2
Question 3
Solution 3
Question 4
Solution 4
Question 5
Solution 5
Question 6
Find
the actual (or true) lower and upper class limits and classmarks (or mid
values) of the following classes: 2.1  4.0, 4.1  6.0 and 6.1  8.0.
Solution 6
Question 7
Observe
the given frequency table to answer the following:
Class Interval

2024

2529

3034

3539

4044

4549

Frequency

6

12

10

15

9

2

a. The true class limits of the
fifth class.
b. The size of the second class.
c. The class boundaries of the
fourth class.
d. The upper and lower limits of
the sixth class.
e. The class mark of the third class.
Solution 7
Question 8
Solution 8
Question 9
Solution 9
Question 10
Solution 10
Question 11
Solution 11
Question 12
Solution 12
Chapter 22  Statistics Exercise Ex. 22.2
Question 1
Solution 1
Question 2
Solution 2
Question 3
Solution 3
Question 4
Solution 4
Question 5
Construct
a frequency distribution table from the given cumulative frequency
distribution showing the weights of 750 students in a school:
Weight (in kg)

c.f.

More Than 25

750

More Than 30

640

More Than 35

615

More Than 40

485

More Than 45

370

More Than 50

220

More Than 55

124

More Than 60

49

More Than 65

24

More Than 70

0

a. Find the number of students
whose weight lie in the interval 4045
b. Find the interval which has the
most number of students.
Solution 5
Frequency distribution table is
as follows:
Weight
(in kg)

c.f.

25
 30

110 (750  640)

30
 35

25 (640  615)

35
 40

130 (615  485)

40
 45

115 (485  370)

45
 50

150 (370  220)

50
 55

96 (220  124)

55
 60

75 (124  49)

60
 65

25 (49  25)

65
 70

24 (24  0)

70
 75

0

a. The number of students whose
weight lie in the interval 40  45 is 115.
b. The interval 45  50 has the
most number of students.
Chapter 22  Statistics Exercise Ex. 22.3
Question 1
Solution 1
Question 2
Solution 2
Question 3
Solution 3
Question 4
Solution 4
Question 5
Solution 5
Question 6
The
daily maximum relative humidity (in per cent) in Mumbai from May 1 to May 7,
1992 is given below:
64, 70, 65, 80, 75, 78
Find the mean.
Solution 6
Question 7
Solution 7
Question 8
Solution 8
Question 9
Solution 9
Question 10
Solution 10
Question 11
Solution 11
Question 12
The
mean of 16 natural numbers is 48. Find the resulting mean, if each of the
number is
a. increased by 5
b. decreased by 8
c. multiplied by 4
d. divided by 0.25
e. increased by 50%
f. decreased by 10%
Solution 12
Question 13
The
mean of 4 observations is 20. If one observation is excluded, the mean of the
remaining observations becomes 15. Find the excluded observation.
Solution 13
Question 14
The
mean monthly income of 8 men is Rs. 8079.75. A man whose monthly income
is Rs. 8280 has
also been taken into consideration. Calculate the mean monthly income of all
the men.
Solution 14
Question 15
The
mean of 200 observations is 20. It is found that the value of 180 is wrongly
copied as 280. Find the actual mean.
Solution 15
Question 16
Solution 16
Question 17
Solution 17
Question 18
Solution 18
Question 19
The following data has been arranged in ascending order.
0, 1, 2, 3, x + 1, x + 5, 20, 21, 26, 29.
Find the value of x, if the median is 5.
Solution 19
Question 20
Solution 20
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