A graduate course has 3 biology students and 4 chemistry students. A sample of 2 students is randomly selected from this class to form a committee. Let X denote the number of biology students who were selected.
1. What are the possible values of X?
2. For each possible value of X, determine its probability.
3. Present the distribution law (the probability mass function) of the random variable X as a table.
4. Depict the probability mass function of X as a bar graph.
5. Calculate the mathematical expectation of X.
6. Calculate the variance of X and the standard deviation of X.
7. Calculate the cumulative distribution function of X.