Question

If 10 is substracted from each of observation then mean of the set of n observation is
1) not affected
2) zero
3) increased by 10
4) decreased by 10​

Answer 1

Answer:

4. Decreased by 10

Step-by-step explanation:

Let the entities be a1 a2 a3 a4 a5 a6.... an

Their mean = a1+a2+a3+a4... an/n= x

Subtracting 10 from each...

Mean = a1-10 + a2 -10.... an-10/n

=[(a1+a2+a3...an)-n×10]/n = x -10

Answer 2

Answer:

3)

explanation):

let sum of observations (Σx)be : x1+x2+x3+....+xn

sum of new observations( Σx'): x1-10+x2-10+...+xn-10=x1+x2+x3+...+xn - n*(10)=Σx -10n

as number of observations will remain same

new mean=(Σx - 10n)/n =previous mean of x-10