answer all questions with explanation

A couple has three children. Suppose the birth of boys and girls is equally likely, let X be the number of girls among the children. Determine the values of X and find the probability distribution of the number of girls X. Use the probability distribution to find 1. The mean or expected number of girls among the three children. 2. The variance of the number of girls X among the three children. 3. The standard deviation of the number of girls X. Use the table below; X P(x) xP(x) (x - ()?P(x)