Measures of Central Tendency- 2 RD Sharma Solutions | Mathematics (Maths) Class 9 PDF Download

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Q u e s t i o n : 2 5
Calculate the mean for the following distribution:
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Q u e s t i o n : 2 5
Calculate the mean for the following distribution:
 
x: 5 6 7 8 9
f: 4 8 14 11 3
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 6
Find the mean of the following data:
 
x: 19 21 23 25 27 29 31
f: 13 15 16 18 16 15 13
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
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Q u e s t i o n : 2 5
Calculate the mean for the following distribution:
 
x: 5 6 7 8 9
f: 4 8 14 11 3
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 6
Find the mean of the following data:
 
x: 19 21 23 25 27 29 31
f: 13 15 16 18 16 15 13
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 7
Find the mean of the following distribution:
 
x: 10 12 20 25 35
f: 3 10 15 7 5
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing . Find the sum of all entries in the second and third column to
obtain N and respectively.
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Page 4


                      
      
       
            
    
 
             
  
 
         
           
     
                   
 
    
Q u e s t i o n : 2 5
Calculate the mean for the following distribution:
 
x: 5 6 7 8 9
f: 4 8 14 11 3
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 6
Find the mean of the following data:
 
x: 19 21 23 25 27 29 31
f: 13 15 16 18 16 15 13
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 7
Find the mean of the following distribution:
 
x: 10 12 20 25 35
f: 3 10 15 7 5
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing . Find the sum of all entries in the second and third column to
obtain N and respectively.
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 8
Five coins were simultaneously tossed 1000 times and at each toss the number of heads were observed. The
number of tosses during which 0, 1, 2, 3,4 and 5 heads were obtained are shown in the table below. Find the mean
number of heads per toss.
 
No. of heads per toss No. of tosses
0
1
2
3
4
5
38
144
342
287
164
25
Total 1000
S o l u t i o n :
The given data can be tabulated in the form
The row of x denotes the number of heads per toss and the row of f denotes the number of tosses.
Prepare the following frequency table of which the first column consists of the number of heads and the second
column the number of tosses frequencies
. Multiply the frequency of each row with the corresponding number of heads to obtain the third column containing
.
Find the sum of all entries in the second and third column to obtain N alreadygiveninthequestion
and respectively. Therefore,
Page 5


                      
      
       
            
    
 
             
  
 
         
           
     
                   
 
    
Q u e s t i o n : 2 5
Calculate the mean for the following distribution:
 
x: 5 6 7 8 9
f: 4 8 14 11 3
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 6
Find the mean of the following data:
 
x: 19 21 23 25 27 29 31
f: 13 15 16 18 16 15 13
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 7
Find the mean of the following distribution:
 
x: 10 12 20 25 35
f: 3 10 15 7 5
S o l u t i o n :
The given distribution in tabulated form is
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing . Find the sum of all entries in the second and third column to
obtain N and respectively.
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
Hence the mean is
Q u e s t i o n : 2 8
Five coins were simultaneously tossed 1000 times and at each toss the number of heads were observed. The
number of tosses during which 0, 1, 2, 3,4 and 5 heads were obtained are shown in the table below. Find the mean
number of heads per toss.
 
No. of heads per toss No. of tosses
0
1
2
3
4
5
38
144
342
287
164
25
Total 1000
S o l u t i o n :
The given data can be tabulated in the form
The row of x denotes the number of heads per toss and the row of f denotes the number of tosses.
Prepare the following frequency table of which the first column consists of the number of heads and the second
column the number of tosses frequencies
. Multiply the frequency of each row with the corresponding number of heads to obtain the third column containing
.
Find the sum of all entries in the second and third column to obtain N alreadygiveninthequestion
and respectively. Therefore,
Hence the mean number of heads per toss is
Q u e s t i o n : 2 9
The mean of the following data is 20.6. Find the value of p.
 
x: 10 15 p 25 35
f: 3 10 25 7 5
S o l u t i o n :
The given distribution in tabulated form is
We have to find the value of p using the information that the mean of the distribution is 20.6.
Prepare the following frequency table of which the first column consists of the values of the variate and the second
column the corresponding frequencies. Multiply the frequency of each row with the corresponding values of
variable to obtain the third column containing .
Find the sum of all entries in the second and third column to obtain N and respectively. Therefore,
The mean is