STAT 212 Business Statistics II 12 6. A contingency table test with 4 rows and 30 degrees of freedom implies that the table must have how many columns? a. 8 b. 9 c. 10 d. 11 e. 12 7. When the necessary conditions are met, a two-tailed test is being conducted to test the difference between two population means, but MINITAB provides only a one-tail area of .036. The correct p-value for this test will be which of the following? a. 0.018 b. 0.009 c. 0.036 d. 0.072 e. 0.964 ANSWER: d 8. To test a claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors’ results in 83 who indicate that they recommend aspirin. The test statistic in this problem is approximately equal to which value below? a. – 1.67 b. – 2.33 c. – 1.86 d. 1.85 e. 2.33 ANSWER: b 9. Given the regression model ŷ = 0.34+10.56 x, where x = sales and y = profit, which of the following gives the correct interpretation of the regression slope? a. A 1–unit increase in profit results in a 0.34 unit increase in sales b. A 1–unit increase in sales results in a 10.90 unit increase in profits c. When sales increases 2 units, profit increases by 21.12 units d. When sales decreases 1 unit, profit increases by 10.56 units e. A 1–unit increase in profit results in a 10.56 unit increase in sales 10. You are given the regression model, profit = 0.35 + 11.54cost, with SSE=1032.5 obtained through a least square method. For the other models below, which of the following may be correct? a. profit = 0.35 + 11.50cost can have SSE < 1032.5 b. profit = 0.30 + 11.54cost can have SSE = 1132.6 c. profit = 12cost + 0.35 can have SSE = 1007.1 d. profit = 0.35 + 11.89cost can have SSE = 1044.04 e. All other models must have SSE ≥ 1032.5

STAT 212 Business Statistics II 13 11. In testing H : µ 1 − µ 2 = 5 vs. H a : µ 1 − µ 2 > 5, the test statistic value z is found to be 1.69. What is the p – value of the test? a. -0.0910 b. 0.0455 c. 0.0910 d. 0.1977 e. 0.3023 12. For a linear regression model profit = 0.35 - 0.95cost where all data points are on this regression line, which of the following is true? a. r xy = - 1 b. r xy = - 0.95 c. b 1 = 0.95 d. r xy = 1 e. b 0 = - 0.35 2 2 13. In testing H o : σ = 5 vs. H a : σ > 5, which of the following is NOT true? a. The test statistics is chi-square with n-2 degrees of freedom b. The underlying variable must be normal c. The true variance is not known d. The sample variance is known e. The true variance must be greater than or equal to 0 14. In contingency table analyses, which of the following is true? a. The variables must be continuous b. The degree of freedom is rc – r – c + 1 c. The variables must be normally distributed d. The attributes in the row and column are independent e. Attributes in the rows are not mutually exclusive 15. Which of the following may be a correct example of a simple linear regression model? a. profit = 0.55(1+1.3Cost) b. profit = 0.80 - 0.95Cost + error c. profit = 0.80 + 0.65Revenue - 0.85Cost + 0.25Revenue*Cost d. profit = 0.80 + 0.45Revenue + 0.20 Revenue 2 + error e. profit = 0.80 + 0.46Revenue - 0.85Cost + error