CISC 7700X Midterm Exam 1. d. Via contraposition, this statement is equivalent to: If something is not in water, then it is not a fish. https://en.wikipedia.org/wiki/Raven_paradox, 2. d 3. Without vaccine, a lot more people would die from smallpox. 4. c 5. b 6. b e.g. return after 3 years: (1+0.35)*(1+0.35)*(1-0.70)=0.54675 (or 54%). geometric mean: ((1+0.35)*(1+0.35)*(1-0.70))^(1/3)=0.81770. return after 3 years using mean: 0.81770^3=0.54674 7. d 8. d 9. e. invalid. 10. a 11. c 12. d: ~7. sqrt(2*5*5). 13. a 14. b 15. e; 8/17 or 0.47059 P(default) = 1/10, P(-default) = 9/10, P(mustache|default) = 8/10, P(-mustache|default) = 2/10, P(mustache|-default) = 1/10, P(-mustache|-default) = 9/10 P(default|mustache) = P(mustache|default)*P(default) / (P(mustache|-default)*P(-default)+P(mustache|default)*P(default)) = ((8/10) * (1/10)) / ( (8/10) * (1/10) + (1/10)*(9/10)) = 8/100 / (8/100 + 9/100) = 8/100 / (17/100) = 8/17 = 0.47059 16. c 17. a 18. b 19. c 20. d