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
1 point
11
13
15
17

Answer 1

Answer:

mean of these observation is

5x+20/5=11

5x+20=55

5x=55-20

5x=35

x=7

now, mean of last 3 observation is

3x+18/3

putting the value of x

3*7+18/3

21+18/3

39/3

=13

hence mean if last 3 term will be 13