2. Missing data problem. Let X = (X1, X2, X3) be a (three-category) multi- nomial random variable with the following probability mass function f(xx | 0) = ($1+ 12 + 13)! 4 + 0 6 r = (31, [2, X3), where 0 E (0, 1) is the unknown parameter. (a) Derive the EM algorithm for estimating the parameter 0 in the above multinomial model (that is, write down the Q-function and maximize it)