Question

The mean of 5 observation x,x+2,x+4,x+6,x+8is 13.Find x Hence find the mean of the last three observation​

Answer 1

CORRECT QUESTION :-

if the mean of five observations x, x+2,x+4,x+6,x+8 is 13 , find the value of x and hence find the mean of the last three observations.

ANSWER :-

➠ mean = sum of all observation / number of observation.

➠ 13 = x+x+2+x+4+x+6+x+8 / 5

➠ 5x + 20 = 65

➠ 5x = 65-20

➠ 5x = 45

➠ $\red{\boxed{\boxed{x = 9}}}$

NOW,

➠ •Calculate the last three observations.

➠$\red{3rd\: observation \:= x +4 = 9+4 = 13}$

➠ $\green{4rd \:observation = x + 6 = 9 +6 = 15}$

➠ $\blue{5rd\: observation = x + 8 = 9+8 =17}$

➠mean (3) = sum of last three observations / number of observation.

➠mean(3) = 13+15+17/3

➠ mean(3) = 45/3

➠$\red{\boxed{\boxed{mean(3) = 15}}}$

➠SO, the mean of the last three observation is 15.