Question

if the mean of 5 observation x,x+2,x+4,x+6,x+8 is 11 find mean of first three observation

Answer 1

HEY MATE!!

YOUR ANS IS HERE... ⤵

Given that mean of 5 observations is 11

We know that

Mean = Sum of observations/No.of observations

x+(x+2)+(x+4)+(x+6)+(x+8)
------------------------------------ = 11
5

5x + 20
----------- = 11
5

5x + 20 = 11 x 5

5x + 20 = 55

5x = 55 - 20

5x = 35

x = 35/5

x = 7

Now Mean of first 3 observations be 'a'

x + (x+2) + (x+4)
---------------------- = a
3



3x + 6
--------- = a
3

Substitute x value in the Above observations

3(7) + 6
------------ = a
3

21 + 6
---------- = a
3

27 = 3a

a = 27/3

a = 9

Therefore the mean of first three observations i.e, x + (x+2) + (x+4) is 9
_____________________

HOPE THIS HELPS U✌✌✋