INDE 2333 Engineering Statistics I Practice Exam 2 INDE 2333 Engineering Statistics I - Practice Exam 2 Instructions: This is an individual effort closed note, closed book, open table exam. You have approximately 80 minutes to complete this exam. The UH Academic Honesty Policy is in effect. Multiple Choice 2 points each - Circle the one and only one best answer. Note that if your answer due to rounding errors is very close to one of the choices you should select that choice. 2. Which of the following encompasses an \"claim\" involved in a hypotheses test. a. b. c. d. Ho Ha Either a or b None of the above 19. An equiprobable approach goodness of fit test with 8 cells for data that is normally distributed with a theoretical given mean of 10 and a std of 2, would have how many degrees of freedom for the critical value? 11. Receiving a false positive on an engineering job interview drug test means the testing facility has? a. b. c. d. a. b. c. d. Committed a type 1 error Committed a type 2 error Made the correct decision None of the above 20. Assuming normality and independence, if n1 or n2 or both are <30 if you cannot reject the Ho in an F test, the next test you are likely to perform is a: 13. Firing an engineer under your supervision for failing a drug test means somebody. a. b. c. d. a. b. c. d. Committed a type 1 error Committed a type 2 error Made the correct decision Either a or c independent t test chi-squared test Smith-Satterthwaite test paired t-test 24. Assuming normality, to determine which comparison of means test to use, you must first run an F test. For this test the Ho: is the variances are the same. The Ha: is the variances are not the same. At an alpha level of 0.10 what is your decision? 14. A statistical test that involves a \"before and after\" focus with 20 subjects has how many degrees of freedom. a. b. c. d. 5 6 7 8 9 19 38 39 a. b. c. d. 1 Cannot reject Ho Reject Ho I need to retake this course Cannot determine from the above information 15. Assuming normality and independence, if n1 or n2 or both are <30, if you have just rejected the Ho in an F test, the next test you are likely to perform is a: a. b. c. d. 25. For the appropriate comparison of means test, calculate the approximate test statistic and determine if you cannot reject or reject the Ho at a 0.01 level assuming normality, independence, and = variance. independent t test chi-squared test Smith-Satterthwaite test paired t-test a. b. c. d. Multiple Choice 4 pts each. 26. If you are suspicious of a claim that one product has at least 50 more operational cycles one the average than another the Ha would be 21. For an equiprobable chi-squared goodness of fit test with an HO of uniformly distributed with the same parameters as the sample for 24 obs., you would have how many degrees of freedom. a. b. c. d. For question 27, the following data represents the number of defects produced before and after quality training in 6 different industrial plants. You would like to see if the training is effective in reducing defects. Before is set 1, after is set 2. Assume normality. 2 3 4 none of the above 22. If you had an equiprobable chi-squared goodness of fit test with an HO of Normally distributed with a given theoretical mean of 12.23 and a given std of 3.54 and you had 4 cells, what would be the critical value at alpha=0.05 a. b. c. d. Cannot reject Ho Reject Ho I need to retake this course None of the above Before 13, 15, 18, 11, 13, 12, 14 After 11, 16, 16, 12, 11, 13, 14 27. What is the null hypotheses? a. b. c. d. 3.841 5.991 7.815 9.488 u1-u2 = 0 uD = 0 or uD<=0 Dbar= 0 uD not =0 34. If you are comparing the means of a new less expensive, but more productive system versus an existing system with unequal variances, using a rational thought process, you would want to determine your critical value degrees of freedom by: a. b. c. d. 2 rounding down rounding up Does not apply Not enough information to decide 2 n E Z / 2 obs exp 2 n S12 F 2 S2 exp i 1 v1 n1 1 s E t / 2 n D D t SD / n t 2 s12 s2 n1 n2 x1 x2 z / 2 v2 n2 1 x s n Z x n v n 1 t X 1 X2 x z / 2 2 S12 S 2 n1 n2 (n 1) s 2 2 v n 1 X2 x z / 2 n n 2 2 s12 s2 n n df 2 12 2 2 ( S1 / n1 ) ( S 2 / n2 ) 2 n1 1 n2 1 D t / 2 s s x z / 2 x z / 2 n n z n / 2 E sD n t X 2 X2 1 1 Sp n1 n2 2 Sp 1 2 (n1 1) S12 (n2 1) S 2 n1 n2 2 df n1 n2 2 x t / 2 s s x t / 2 n n x1 x2 t / 2 3 2 (n1 1) s12 (n2 1) s2 n1 n2 2 1 1 n1 n2 n