Question

28. Answer the following questions:
1) The mean of 10 observations is 12.5. If the mean of 4 observations of them is 5 find the mean
of remaining observations.​

Answer 1

Step-by-step explanation:

The sum of firs 6 numbers is

=15×6

=90

Thereforex 1 +x 2 +...x 6 =90 ...(i)

And

The sum of last five number is

=10×5

=50

Therefore

x 10 +x 9 +x 8 ...x 6 =50 ...(ii)

Sum of all number is

=12.5×10

=125 ...(iii)

Hence

i+ii

=140

=(x 1+x 2 +....x 10) +x 6

=125+x 6

Or

x 6 =15.