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Unformatted text preview: STA 3024 Exam 1 Sample Questions 1. In a chisquared test for a contingency table, which of the following corresponds to having little or no evidence that the response variable depends on the explanatory variable? (A) a small value of the X 2 test statistic (B) a small pvalue (C) both (A) and (B) (D) neither (A) nor (B) 2. Suppose we’re comparing the effectiveness of three different pain medications (aspirin, ibuprofen, and naproxen) for relieving headaches. A random sample of 204 subjects is summarized by the following contingency table: Relief Medication Yes No Total Aspirin 29 30 59 Ibuprofen 86 17 103 Naproxen 33 9 42 Total 148 56 204 Calculate the residual for the “Aspirin, No” cell. (A) 16 . 2 (B) 13 . 8 (C) 11 . (D) 13 . 8 (E) 16 . 2 3. For the data shown in the following contingency table, what is the sample difference between proportions of seniors and juniors who passed the exam? Exam Result Class Year Pass Fail Senior 99 10 Junior 36 33 (A) 0.39 (B) 0.47 (C) 0.50 (D) 0.58 (E) 0.82 4. Consider the conditional distribution in the following contingency table: Result Medication Cured Not cured Total Medication I 74% 26% 100% Medication II 60% 40% 100% True or false: In this sample, 74% of patients who were cured took Medication I. (A) True (B) False 5. Which of the following data sets would be most immediately suitable for representation as a contingency table? (A) Surgery Recovery Time (Explanatory) (Response) Procedure B 5 days Procedure B 11 days Procedure C 4 days . . . . . . Procedure A 11 days (B) Surgery Anesthesia (Explanatory) (Response) Procedure A Local Procedure A General Procedure B General . . . . . . Procedure A Local (C) Age of Patient Recovery Time (Explanatory) (Response) 61 17 days 31 19 days 56 23 days . . . . . . 21 12 days (D) Age of Patient Anesthesia (Explanatory) (Response) 67 Local 55 General 21 Local . . . . . . 27 Local 6. We are investigating whether the presence of a certain disease is related to blood type. Suppose we could calculate the conditional distribution of disease status given blood type for the entire population . In which of the following two situations would the population conditional distribution indicate that disease status and blood type are independent? Disease Status Blood Type Present Absent AB 3% 97% A 2% 98% B 2% 98% O 1% 99% Situation I Disease Status Blood Type Present Absent AB 50% 50% A 0% 100% B 50% 50% O 0% 100% Situation II (A) Situation I only (B) Situation II only (C) both Situation I and Situation II (D) neither Situation I nor Situation II 7. Which of the following contingency tables would yield a larger value of the X 2 test statistic? (Note: In both tables, the expected count for each cell is 8.) Response Gender Yes No Male 10 6 Female 6 10 Table I Response Gender Yes No Male 6 10 Female 10 6 Table II (A) Table I (B) Table II (C) Both tables would yield the same value of X 2 ....
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 Spring '08
 TA
 Statistics, Fisher's exact test, Chisquared test

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