Question

8. The mean of 9 observations is 13. The mean of fist 5 observations is 11 and mean of last 5 observations is 14. Find the one observation​

Answer 1

$\bold{ANSWER≈}$

9

if we add 9 numbers =9*9=81

first 5 numbers added to 10*5=50

last 5 numbers added to 8*5=40

If we add last two conditions total is 50+40=90

here all 9 numbers are added and also 5th number once more added

so 5th observation is 90–81=9