2. The following contingency table shows the number of adults with credit scores 725 or above and below 725 as well as their marital status.

a) Construct a decision tree for this table. (with explanation)

b) Use the decision tree to find the following: probability that a randomly selected adult is married, given that their credit score is below 725. (solve with explanation)

Credit score Single (S) Married (D)

Below 725 (A) 39 33

725 and above (B) 15 63