Question

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

Answer 1

Heya !

Here's your answer !!

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GIVEN THAT :

Mean of 5 observations is 11

Observations : x , x + 2 , x + 4 , x + 6 + x + 8

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TO FIND :

Mean of first 3 observations.


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SOLUTION :

First, well find the value of x.

=> $\frac{ x + x + 2 + x +.4 + x + 6 + x + 8}{5}\:$ = 11

=> $\frac{5x + 20 }{5}\:$ = 11

=> 5x + 20 = 11 × 5

=> 5x = 55 - 20

=> x = 35/5

=> x = 7


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Now, putting the value of x, we get the observations :

7 , 9 , 11 , 13 and 15



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Mean of first 3 observations :

=> $\frac{7+9+11}{3}$

=> $\frac{27}{3}$

=> 9 ANS



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THANKS !!

Answer 2

ANSWER

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Mean of 5 observations = 11

Observations are as follows : x , x + 2 , x + 4 , x + 6 + x + 8


We have to find :

Mean of first 3 observations.



SOLUTION is :



=> $\frac{ x + x + 2 + x +.4 + x + 6 + x + 8}{5}\:$ = 11

=> $\frac{5x + 20 }{5}\:$ = 11

=> 5x + 20 = 11 × 5

=> 5x = 55 - 20

=> x = 35/5

=> x = 7

The observations are :

7 , 9 , 11 , 13 and 15


Mean of first 3 observations =

=> $\frac{7+9+11}{3}$

=> $\frac{27}{3}$

=> 9



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