15. Which of the following statements is are correct regarding the concept of "decision trees?" a. they are graphical tools b. they are used to compute the EMVS c. they are used when risks are known d. they will yield the same outcomes as decision tables e. all of these f. none of these 16. Which of the following statements is are correct regarding the concept of "non-statistical sampling techniques?" a. it is one's judgment | b. guess c. convenience d. trusting one's gut e. all of these f. none of these