Question
The mean of 5 observations is 12. If the mean of the first 3 observations is 10, then find the mean of the other two.
Answer: Option D
:
D
Let, the observations be a, b, c, d, e.
We know that,
Mean = SumofallobservationsNumberofobservations
Now,
mean of 5 observations = 12
⇒a+b+c+d+e5=12
⇒a+b+c+d+e=60.....(i)
It is also given that the mean of the first three observations is 10
⇒a+b+c3=10
⇒a+b+c=30...........(ii)
From (i) and (ii) we get
d + e = 30
Hence, the mean of the other two observations i.e. 'd' and 'e' is
=d+e2=15
Was this answer helpful ?
:
D
Let, the observations be a, b, c, d, e.
We know that,
Mean = SumofallobservationsNumberofobservations
Now,
mean of 5 observations = 12
⇒a+b+c+d+e5=12
⇒a+b+c+d+e=60.....(i)
It is also given that the mean of the first three observations is 10
⇒a+b+c3=10
⇒a+b+c=30...........(ii)
From (i) and (ii) we get
d + e = 30
Hence, the mean of the other two observations i.e. 'd' and 'e' is
=d+e2=15
Was this answer helpful ?
Submit Solution