1.
The mean of 5 observations is 15. If mean of the first three observations is 14 and
that of the last three is 17. Find the third observation.©
Answers
≡QUESTION≡
The mean of 5 observations is 15. If mean of the first three observations is 14 and that of the last three is 17. Find the third observation.
║⊕ANSWER⊕║
GIVEN
Mean of 5 observations is 15.
∴ The sum of observations = 15 * 5
= 75
GIVEN
Mean of the first 3 observations is 14
∴ The sum of first three observations = 14 * 3
= 42
GIVEN
Mean of the last 3 observations is 17.
∴ The sum of the last three observations = 17 * 3
= 51
Hence,
The third observation = (42 + 51) - 75
= 93 - 75
= 18