Exercise 2. 1. Let S:= exp(X) where X is a normal distribution with parameters p and of. Prove that S has the following density function (inis) - 2 f (s) = e , if s > 0 and 0 otherwise. V2nSO 2. Compute E[S]. 3. We have a sample of the size of concrete particles in micrometer 3.1;5.0;8.9; 16.0;25.6;39.1; 109.2. Give an estimator of u if we assume that the size of a particule concrete follows the distribution of S with a fix parameter o = 0.7