Stat 2300 International, Fall 2006– Sample Midterm Answers
Friday, October 20, 2006
. 1. d. variable.
2. b. sampling without replacement.
3. d. Statistical Inference
4. a. Outliers
5. c. three
6. d. Z-score
7. a. Independent events
8. b. mutually exclusive.
9. b. P(A | B) = P(A)
10. b. Poisson random variable
11. b. (n) (p).
12. a. its outcomes are countable.
13. b. zero, one.
14. d. Poisson and exponential
15. d. below the mean.
16. c. for any sample size.
17. b. increases, normal
18. d. .09 and 1.34
19. b. the t distribution.
20. b. size is large.
21. z = (33.2-32)/.8 = 1.5; value from table = 0.4332;
Probability = 0.5 + 0.4332 = 0.9332 = 93.32%
22. (i) 9.6 (ii) 10 (iii) 10
23. [mean = 10] (i) 10 (ii) 11.6 (iii) about 3.41
24. Probability = .95*.92 = .874 = 87.4%
25. [P(B) = .4, P(M) = .5, P(B|M) = .2]
P(B∩M) = P(M)*P(B|M) = .5*.2 = .1 = 10%
26. Expected Outcome = .25*(-40,000) + .7*10,000 + .05*70,000 = $500
27. Probability = 10! / (10! * 0!) * .9^10 * .1^0 = .3487 = 34.87%
28. 1 – P(x = 0) = 1 – e^(-2) * 2^0 / 0! = 1- .1353 = 0.8647 = 86.47%
