Common discrete distributions include
• Uniform(0,n), p(x) = \frac{1}{n}, x = 0,1,..., n,
• Poisson(?), p(x) = \frac{?^x e^{-?}}{x!}, x = 0, 1, ..., ?,
• Bernoulli(p), p^x(1 - p)^{1-x}, x = 0, 1,
• Binomial(n, p), p(x) = \binom{n}{x}p^x(1 - p)^{n-x}, x = 0, 1, ..., n,
• Geometric(p), p(x) = p(1 - p)^x, x = 0,1,...,?,
• Negative Binomial(m,p), p(x) = \binom{m+x-1}{m}p^m(1-p)^x, x = 0,1,..., ?,
Please find the moment generating function of these distribution laws. Use it to calculate the first 4 moments,
then calculate the variance and skewness.