Question

the sum of deviations of 'n' observations from 25 is 25 and sum of deviations of the same 'n' observations from 35 is -25.find the mean of the observation

Answer 1

Answer:

Given,

no. of observations=n

Let assumed mean=25

sum of deviations = 25

actual mean = 25+(25/n)

Same way

actual mean =35+(-25/n)

so

25+(25/n)=35-(25/n)

25-35=-(25/n)-(25/n)

-10=-50/n

n=-50/-10

n=5

mean=25+(25/n)

=25+(25/5)

=25+5

=30