MENU
Question -

In question 1(iii), (iv), (v) find the number of observations lying between  –M.D and +M.D, where M.D. is the mean deviation from the mean.



Answer -

(iii) 34,66, 30, 38, 44, 50, 40, 60, 42, 51

We know that,

MD=

Where, |di| = |xi – x|

So, let ‘x’ be the mean of the given observation.

x = [34 + 66 + 30 + 38 + 44 + 50 + 40 + 60 + 42 + 51]/10

= 455/10

= 45.5

Number of observations, ‘n’ = 10

xi

|di| = |xi – 45.5|

34

11.5

66

20.5

30

15.5

38

7.5

44

1.5

50

4.5

40

5.5

60

14.5

42

3.5

51

5.5

Total

90

MD=

= 1/10 × 90

= 9

Now

M.D = 45.5 – 9 = 36.5

+M.D = 45.5 + 9 = 54.5

So,There are total 6 observation between M.D and +M.D

(iv) 22, 24,30, 27, 29, 31, 25, 28, 41, 42

We know that,

MD=

Where, |di| = |xi – x|

So, let ‘x’ be the mean of the given observation.

x = [22 + 24 + 30 + 27 + 29 + 31 + 25 + 28 + 41 + 42]/10

= 299/10

= 29.9

Number of observations, ‘n’ = 10

xi

|di| = |xi – 29.9|

22

7.9

24

5.9

30

0.1

27

2.9

29

0.9

31

1.1

25

4.9

28

1.9

41

11.1

42

12.1

Total

48.8

MD=

= 1/10 × 48.8

= 4.88

Now

So, There are total 5 observation between and

(v) 38, 70,48, 34, 63, 42, 55, 44, 53, 47

We know that,

MD=

Where, |di| = |xi – x|

So, let ‘x’ be the mean of the given observation.

x = [38 + 70 + 48 + 34 + 63 + 42 + 55 + 44 + 53 + 47]/10

= 494/10

= 49.4

Number of observations, ‘n’ = 10

xi

|di| = |xi – 49.4|

38

11.4

70

20.6

48

1.4

34

15.4

63

13.6

42

7.4

55

5.6

44

5.4

53

3.6

47

2.4

Total

86.8

MD=

= 1/10 × 86.8

= 8.68

Now

Comment(S)

Show all Coment

Leave a Comment

Free - Previous Years Question Papers
Any questions? Ask us!
×