Question

The mean of first 5 observations is 20 and the mean of last 5

observations is 45. What is mean of all 10 observations?​

Answer 1

Answer:

Given Mean of 10 observations is 20

⟹Sum of 10 observations is S=20×10=200

If each observation is added by 5 Then sum of observations is added by 5×10=50

⟹S

′

=200+50=250

Mean of new observation is

10

S

′

=

10

250

=25