Question

If the mean of 5 observations x , x +2 , x +4 , x +6 and x +8 is 11 , then the mean of last three observations is

Answer 1

Answer:

Mean= {x+(x+2)+(x+4)+(x+6)+(x+8)}/5=11

(5x+20)/5=11

x+4=11

x=7

Mean of last three observation={x+4+x+6+x+8}/3

=(3x+18)/3=x+6

Now put the value of x =7 in x+6

New mean=7+6=13