Question

I WILL YOU MARK YOU AS BRAINLIEST if the mean of five observations x , x+2 , x+4,x+6,x+6 is 11 find the mean of first three observation

Answer 1

Note: it should be x + 8 instead of x + 6. It follows a series.

Given observations are x, x + 2, x + 4, x + 6, x + 8 = 11.

Total observations = 5.

mean = 11.

Now,

We know that Mean = Sum/Total number of observations

⇒ 11 = (x + x + 2 + x + 4 + x + 6 + x + 8)/5

⇒ 55 = 5x + 20

⇒ 35 = 5x

⇒ x = 7

Mean of first three observations = (x + x + 2 + x + 4)/3

⇒ (3x + 6)/3

⇒ 3(x + 2)/3

⇒ x + 2

⇒ 7 + 2

⇒ 9.

Therefore, Mean of first three observations = 9.

Hope it helps!

Answer 2

You are written x+6 two times. I think one x+6 is x+8 if so following is the answer

(x+x+2+x+4+x+6+x+8)/5  = 11

5x + 20 = 55

5x = 55 - 20

x = 35/5 = 7

three observation = x,x+2,x+4 = 7,9,11

mean = (7+9+11)/3 = 9       0r  (x+x+2+x+4)/3 = (3x+6)/3 = (21+6)/3 = 27/3 = 9