CBSE Guess > Papers > Important Questions > Class IX > 2011 > Maths > Mathematics By Mr. Amit Kumar Jha
CBSE CLASS IX
Statistics
Section A
 The value of π up to 50 decimal places is given below: 3.14159265658979323846264338327950288419716939937510 (i) make the frequency distribution of the digits from o to 9 after the decimal point.
(ii) What are the most and the least frequency occurring digits?
 A company manufactures car batteries of a particular type. The lives (in years) of 40 such batteries were recorded as follows:
Construct a grouped frequency distribution table for this data, using class intervals of size 0.5 starting from the interval 22.5.
 The length of 40 leaves of a plant are measured correct to one millimeter, and the obtained data is represented in the following table:
Length ( in mm) 
Numbers of Leaves 
18126 
3 
127135 
5 
136144 
9 
145153 
12 
154162 
5 
163171 
4 
172180 
2 
(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 numbers of leaves are 153mm long? Why?
 A random survey of the number of children of various age groups playing in a park was found as follows:
Age (in years) 
Numbers of children 
12 
5 
23 
3 
35 
6 
57 
12 
710 
9 
1015 
10 
1517 
4 
Draw a histogram to represent the data above
Secion B
 The height (in cm) of 9 students of a class are as follows:155 160 145 149 150 147 152 144 148; Find the median of this data.
 The points scored by a Kabaddi team in a series of matches are as follows:17, 2, 7, 27, 15, 5, 14, 8, 10, 24, 48, 10, 8, 7, 18, 28 Find the median of the points scored by the team.
 Find the mode of the following marks (out of 10) obtained by 20.4, 6, 5, 9, 3, 2, 7, 7, 6, 5, 4, 9, 10, 10, 3, 4, 7, 6, 9, 9.
 The following number of goals were scored by a team in a series of 10 matches 2, 3, 4, 5, 0, 1, 3, 3, 4, 3 Find the mean, median, mode of those scores.
 In a mathematics test given to 15 students, the following marks (out of 100) are: 41, 39, 48, 52, 46, 62, 54, 40, 96, 52, 98, 40, 42, 52, and 60 Find the mean, median, mode of those scores.
 The following observations have been arraigned in ascending order. If the median of the data is 63, find the value of x.29, 32, 48, 50, x, x+2, 72, 78, 84, 95
 Find the mean salary of 60 workers of a factory from the following table:
Salary (in Rs) 
Number of workers 
3000 
16 
4000 
12 
5000 
10 
6000 
8 
7000 
6 
8000 
4 
9000 
3 
10000 
1 
Total 
60 
 Find the missing (?) frequencies in the following frequency distribution if it is known that the mean of the distribution is 1.46.
Number of accidents (x): 
0 
1 
2 
3 
4 
5 
Total 
Frequency (f): 
46 
? 
? 
25 
10 
5 
200 
Submitted By Amit Kumar Jha
Email Id : jhabai@hotmail.com 
