Question

if mean of observations x, x+2,x+4,x+6,x+8is11 find the value of x
2)the mean of first three observations ​

Answer 1

Answer:

Step-by-step explanation:

Given,

Mean of "x , x + 2 , x + 4 , x + 6 , x + 8 " is 11

To Find :-

1) Value of 'x'

2) Mean of first three observations

Formula Required :-

Mean = $\sf\dfrac{sum\: of\: the\: observations}{number\: of\: the\: observations}$

Solution :-

Sum of the observations = x + x + 2 + x + 4 + x + 6 + x + 8

= 5x + 20

= 5(x + 4)

Number of Observations = 5

Mean = $\sf\dfrac{5(x + 4)}{5}$

11 = x + 4

x = 11 - 4

x = 7

Since, Value of 'x' = 7.

Mean of First three observations = Sum of first three observations / 3

Sum of first three observations =

= x + x + 2 + x + 4

= 3x + 6

= 3( x + 2)

= 3(7 + 2)

= 3(9)

= 27

Mean of first three observations = 27/3

= 9

Since , Mean of first three observations = 9