When calculating Joint, Marginal, and Conditional probabilities with "unknown" values like the table below, should they be included in the totals? or are they ignored when calculating the probabilities?
For example, what is the probability that the offender is at least 18 if we known the victim was at least 18 (I'm not asking for the specific answer to this question but rather the inclusion/exclusion of the Unknown)?
Would it be $$P = \frac{Joint Probability}{Marginal Probability} = \frac{\frac{4870}{5924}}{\frac{5180}{5924}} = \frac{.82}{.87} = .94$$ Or $$P = \frac{Joint Probability}{Marginal Probability} = \frac{\frac{4870}{6434}}{\frac{5579}{6434}} = \frac{.76}{.87} = .87$$
