3. For any discrete RV, the probabilities specied by the probability formula must add up to one as you consider all values in the support. That is, 1 = Z P(X = 2:). For each of the below distributions, zEsupport show that the probabilities add up to 1. In each case, you will need to use some important fact / result from your previous mathematics coursework. Make sure you explicitly note the fact as you use it; you don't need to re-derive/prove the fact. a. X N Geom(p) (Hint: Fact usually seen in Algebra 2, Precalculus, and 20B classes) b. X N Binom(n, p) (Hint: Fact usually seen when learning induction in Algebra 2 or Precalculus) c. X N Poe's\") (Hint: Fact rst seen near the end of 20B)