Question

29. The first three moments of a distribution about the value 5 are 2, 20 and 40. Third
moment about the mean is
(2)
(B) 64
(C) 32
(D) -32
(A) -64

Answer 1

Answer:

Answer is B = 64 is right answer

Answer 2

Option D is the correct answer for 64.

Let ′r=E(xi5)r be the rth moment of a variable x around 5 and r=E(xix)r be the rth moment of x around its mean.

Consider the term "mean" for a moment. = μ2=E(xi−x¯) 2=E(xi−7) 2=E[(xi−5)+(5−7)] 2=E[(xi−5)−2] 2=E(xi−5) 24E(xi5) +4=′24′ 1+4=2042+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4=204+4= 16 ..

The distribution has been negatively skewed since the age of ten, and platykurtic since the age of twenty-three.