Maximum likelihood estimation

Question

The random variables X1,X2,…,Xn are continuous, independent, and distributed according to the Erlang PDF

fX(x)=[λ^3*x^2*e^(−λx)]/2, for x≥0,

where λ is an unknown parameter. Find the maximum likelihood estimate of λ, based on observed values x1,x2,…,xn . Express your answer as a function of n and s where s=x1+x2+…xn .

λ^ML=..?

Answer 1

Anyone has a clue about this?

Answer 2

3*n/s