Question

The first two moments of a distribution about the value of 5 of the variable are 2 and 20. Find the menu and the variance

Answer 1

Answer:

Let rth moment of a variable x about 5 is μ′r=E(xi−5)r and let rth moment of x about its mean be μr=E(xi−x¯)r.

So, μ′1=2⇒E(xi)−5=2⇒E(xi)=x¯=2+5=7

So, first moment about mean = μ1=E(xi−x¯)=E(xi)−x¯=7−7=0...(1)