1.
The relative
humidity (in %) of a certain city for a month of 30 days was as follows:
|
98.1
|
98.6
|
99.2
|
90.3
|
86.5
|
95.3
|
92.9
|
96.3
|
94.2
|
95.1
|
|
89.2
|
92.3
|
97.1
|
93.5
|
92.7
|
95.1
|
97.2
|
93.3
|
95.2
|
97.3
|
|
96.2
|
92.1
|
84.9
|
90.2
|
95.7
|
98.3
|
97.3
|
96.1
|
92.1
|
89
|
(i) Construct a grouped
frequency distribution table with classes 84 - 86, 86 - 88, etc.
(ii) Which month or season do
you think this data is about?
(iii) What is the range of this
data?
2.
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:
|
Number of
letters
|
1 - 4
|
4 - 6
|
6 - 8
|
8 - 12
|
12 - 20
|
|
Number of
surnames
|
6
|
30
|
44
|
16
|
4
|
(i) Draw a histogram to depict
the given information.
(ii) Write
the class interval in which the maximum number of surnames lie.
3.
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)
|
118 - 126
|
127 - 135
|
136 - 144
|
145 - 153
|
154 - 162
|
163 - 171
|
172 - 180
|
|
Number of
leaves
|
3
|
5
|
9
|
12
|
5
|
4
|
2
|
(i) Draw a histogram to
represent the given data.
(ii)Also represent by a polygon
( Separately )
(iii) Is it correct to conclude
that the maximum number of leaves are 153 mm long? Why?
4.
Find out mean, mode ( Calculate).
|
Marks
|
10
|
20
|
30
|
40
|
50
|
60
|
70
|
|
Number of students
|
7
|
10
|
10
|
17
|
23
|
15
|
8
|
5.
Find the value of p if mean is 7.5
|
Marks
|
3
|
5
|
7
|
9
|
11
|
13
|
|
Number of students
|
6
|
8
|
15
|
p
|
8
|
4
|
6.
Find the value of ‘m’ and ‘n’ if mean is 50 and total observations are 90.
|
Class Marks
|
10
|
30
|
50
|
70
|
90
|
|
Number of students
|
17
|
m
|
32
|
n
|
19
|
7.
Find median
of
20,26,8,18,24,18,46,23,62,55,70,44
8.
The class mark
for a certain continuous frequency distribution are . find class intervals and
draw hisrogram.
|
Class Marks
|
6
|
12
|
18
|
24
|
30
|
|
Number of students
|
12
|
15
|
20
|
9
|
16
|
9.
The mean of
a data is 46. Find the new mean if each
of the observation of a data is
(a) increased by 3 (b) decreased by 2 (c) multiplied by 0.5
10.
Find less
than and more than cumulative frequency.
|
Number of
letters
|
0 - 4
|
4 - 8
|
8 - 12
|
12 - 16
|
16 - 20
|
|
Number of
surnames
|
6
|
17
|
23
|
13
|
11
|
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