English

Find the mean deviation about the mean of the following data: Size (x): 1 3 5 7 9 11 13 15 Frequency (f): 3 3 4 14 7 4 3 4 - Mathematics

Advertisements
Advertisements

Question

Find the mean deviation about the mean of the following data:

Size (x): 1 3 5 7 9 11 13 15
Frequency (f): 3 3 4 14 7 4 3 4
Sum
Advertisements

Solution

Mean = `barx = (f_i  x_i)/(f_i)`

= `(3 + 9 + 20 + 98 + 63 + 44 + 39 + 60)/42`

= `336/42`

= 8

M.D. `(barx) = (f_i |x_i - barx|)/(f_i)`

= `(3(7) + 3(5) + 4(3) + 14(1) + 7(1) + 4(3) + 3(5) + 4(7))/42`

= `(21 + 15 + 12 + 14 + 7 + 12 + 15 + 28)/42`

= `62/21`

= 2.95

shaalaa.com
  Is there an error in this question or solution?
Chapter 15: Statistics - Solved Examples [Page 272]

APPEARS IN

NCERT Exemplar Mathematics [English] Class 11
Chapter 15 Statistics
Solved Examples | Q 1 | Page 272

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Find the mean deviation about the mean for the data.

38, 70, 48, 40, 42, 55, 63, 46, 54, 44


Find the mean deviation about the median for the data.

36, 72, 46, 42, 60, 45, 53, 46, 51, 49


Find the mean deviation about the mean for the data.

Income per day in ₹ Number of persons
0-100 4
100-200 8
200-300 9
300-400 10
400-500 7
500-600 5
600-700 4
700-800 3

Find the mean deviation about the mean for the data.

Height in cms Number of boys
95 - 105 9
105 - 115 13
115 - 125 26
125 - 135 30
135 - 145 12
145 - 155 10

Calculate the mean deviation about the median of the observation:

 38, 70, 48, 34, 42, 55, 63, 46, 54, 44


Calculate the mean deviation about the median of the observation:

 38, 70, 48, 34, 63, 42, 55, 44, 53, 47

 

Calculate the mean deviation from the mean for the  data:

 13, 17, 16, 14, 11, 13, 10, 16, 11, 18, 12, 17


Calculate the mean deviation from the mean for the  data:

(iv) 36, 72, 46, 42, 60, 45, 53, 46, 51, 49

 

The lengths (in cm) of 10 rods in a shop are given below:
40.0, 52.3, 55.2, 72.9, 52.8, 79.0, 32.5, 15.2, 27.9, 30.2 

Find mean deviation from the mean also.

 

 


In  22, 24, 30, 27, 29, 31, 25, 28, 41, 42 find the number of observations lying between 

\[\bar { X } \]  − M.D. and

\[\bar { X } \]   + M.D, where M.D. is the mean deviation from the mean.


In 38, 70, 48, 34, 63, 42, 55, 44, 53, 47 find the number of observations lying between

\[\bar { X } \]  − M.D. and

\[\bar { X } \]   + M.D, where M.D. is the mean deviation from the mean.


Find the mean deviation from the mean for the data:

xi 5 10 15 20 25
fi 7 4 6 3 5

Find the mean deviation from the mean for the data:

Size 20 21 22 23 24
Frequency 6 4 5 1 4

Find the mean deviation from the mean for the data:

Classes 0-100 100-200 200-300 300-400 400-500 500-600 600-700 700-800
Frequencies 4 8 9 10 7 5 4 3

 


Find the mean deviation from the mean for the data:

Classes 95-105 105-115 115-125 125-135 135-145 145-155
Frequencies 9 13 16 26 30 12

 


Find the mean deviation from the mean for the data:

Classes 0-10 10-20 20-30 30-40 40-50 50-60
Frequencies 6 8 14 16 4 2

Compute mean deviation from mean of the following distribution:

Mark 10-20 20-30 30-40 40-50 50-60 60-70 70-80 80-90
No. of students 8 10 15 25 20 18 9 5

The age distribution of 100 life-insurance policy holders is as follows:

Age (on nearest birth day) 17-19.5 20-25.5 26-35.5 36-40.5 41-50.5 51-55.5 56-60.5 61-70.5
No. of persons 5 16 12 26 14 12 6 5

Calculate the mean deviation from the median age


Find the mean deviation from the mean and from median of the following distribution:

Marks 0-10 10-20 20-30 30-40 40-50
No. of students 5 8 15 16 6

Calculate mean deviation about median age for the age distribution of 100 persons given below:

Age: 16-20 21-25 26-30 31-35 36-40 41-45 46-50 51-55
Number of persons 5 6 12 14 26 12 16 9

Calculate mean deviation from the median of the following data: 

Class interval: 0–6 6–12 12–18 18–24 24–30
Frequency 4 5 3 6 2

The mean of 5 observations is 4.4 and their variance is 8.24. If three of the observations are 1, 2 and 6, find the other two observations.

 

For a frequency distribution mean deviation from mean is computed by


The mean deviation of the series aa + da + 2d, ..., a + 2n from its mean is


Find the mean deviation about the mean of the distribution:

Size 20 21 22 23 24
Frequency 6 4 5 1 4

Find the mean deviation about the median of the following distribution:

Marks obtained 10 11 12 14 15
No. of students 2 3 8 3 4

Mean and standard deviation of 100 items are 50 and 4, respectively. Find the sum of all the item and the sum of the squares of the items.


Find the mean and variance of the frequency distribution given below:

`x` 1 ≤ x < 3 3 ≤ x < 5 5 ≤ x < 7 7 ≤ x < 10
`f` 6 4 5 1

Determine mean and standard deviation of first n terms of an A.P. whose first term is a and common difference is d.


The sum of squares of the deviations of the values of the variable is ______ when taken about their arithmetic mean.


The mean and variance of seven observations are 8 and 16, respectively. If 5 of the observations are 2, 4, 10, 12, 14, then the product of the remaining two observations is ______.


Find the mean deviation about the mean for the data.

xi 5 10 15 20 25
fi 7 4 6 3 5

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×