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STATISTICS
(a) How many students are at least 12 years old but less
than14 years old.
1 . The water bills of 32 houses in a locality are as follows. Construct
(b) How many students are at least 14 years in age ? Ans 96
a frequency table using a class size of 10.
12, 13, 45, 65, 76, 78, 34, 35, 54, 76, 87, 98, 11, 23, 34, 33, 22, 34,
Ans 94
7. The distribution of weights of 40 students in a class are given
56, 76, 44, 33, 21, 54, 77, 81, 12, 22, 35, 44, 15, 65.
Weight in
2. Find the mean and median of all the positive factors of 48.
36-40
41-45
46-50
51-55
56-60
61-65
3
6
5
10
9
7
kg
Ans: 12.4; 7
No. of
students
3. The mean age of 12 boys is 10 years. It was founded that the age
of one boy was taken as 14 years instead of 12 years. Find the
correct mean.
Ans: 9 year 10 months
4. The mean weight of 8 students is 46.5kg .Three more students
Draw a histogram and a frequency polygon for the distribution.
8. Form a frequency table for the following data:
having weights 41.7kg, 52 .8kg and 51.8kg joined the group. What is
the new mean weight of students?
Ans: 47.12 kg
Marks
No. of
5. The following observations have been arranged in ascending order.
>0
30
> 10
>20
>30
>40
>50
26
21
14
10
0
students
If the median of the data is 48.5 find the value of x.
16, 20, 24, 29, 30, 40, x, 50, 60, 72, 81, 91.
Ans: 47
mean is 198.find the value of the excluded observation.
6. The age of 300 students of a school are given
Age in yrs Below
No.of
9. Mean of 15 observations is 200.If one observation is excluded their
Below
Below
Below
Belpw
10
12
14
16
18
45
116
210
275
300
students
Construct a frequency table of the data. Also
Ans :228
10. The number of goals scored by a football team in a series are as
follows 3,1,0,7,5,3,3,4,1,2,0,2. Find the median of the data.
Ans 2.5