PRACTICE MULTIPLE CHOICE QUESTIONS FOR THE FINAL EXAM (Solutions are at the end) 1. A population is a set of existing units. A) True B) False 3. An example of a quantitative variable is the make of a car. A) True B) False 4. An example of a qualitative variable is the mileage of a car. A) True B) False 5. Which of the following is a quantitative variable? A) The Make of a TV D) Whether a person is a College Graduate B) A Person's Gender E) Whether a Person Has a Charge Account C) Mileage of a Car 6. Which of the following is a categorical variable? A) Air Temperature D) Whether a Person Has a Traffic Violation B) Bank Account Balance E) Value of Company Stock C) Daily Sales in a Store 7. Measurements from a population are called A) Statistics B) Observations C) Finite Populations D) Runs plots 8. The median is the measure of central tendency that divides a population or sample into four equal parts. A) True B) False 9. The population mean is the average of the population measurement. A) True B) False 10. The median is said to be resistant to extreme values. A) True B) False 11. The median is the value below which and above which approximately 50 percent of the measurements lie. A) True B) False 12. Range is a better measure of variation than standard deviation. A) True B) False 13. Another name for the 50th percentile is the _____. 14. A histogram that tails out towards larger values is skewed _____. 15. A histogram that tails out towards smaller values is skewed _____. 16. A numeric characteristic of a sample is a A) Mean B) Variance C) Statistic D) Parameter 17. Which percentile describes Q1? A) 25th B) 50th C) 75th D) 100th 18. Which percentile describes Q3? A) 25th B) 50th C) 75th D) 100th 19. The mean and median are the same for a normal distribution. A) True B) False 20. The mean life of pair of shoes is 40 months with a standard deviation of 8 months. If the life of the shoes is normally distributed, how many pairs of shoes out of one million will need replacement before 36 months? A) 500,000 B) 808,500 C) 191,500 D) 308,500 21. A standard normal distribution has a mean of _____ and standard deviation of _____. A) zero, zero B) zero, one C) one, one D) one, zero 22. The area under the normal curve between z = 0 and z = 1 is ________________ the area under the normal curve between z =1 and z = 2. A) Less than B) Greater than C) Equal to D) A, B, or C above dependent on the value of the mean E) A, B, or C above dependent on the value of the standard deviation 23. A student's grade on an examination was transformed o a z value which is negative. Therefore, we know that he scored: A) Higher than 16% of the class D) Below the mean B) Higher than 45% of the class E) Lower than 16% of the class C) Above the first quartile 24. If a given population has a mean and standard deviation of 48 and 16 respectively, then, the mean and the standard deviation for the sampling distribution of for n = 16 are: A) 4 and 1 B) 12 and 4 C) 48 and 4 D) 48 and 1 E) 48 and 16 25. A manufacturing company measures the weight of boxes before shipping them to the customers. If the box weight have a population mean and standard deviation of 90 lbs. and 24 lbs. respectively, then the probability that a sample mean weight will exceed 94 lbs., based on a sample size of 36 boxes is: A) 34.13% B) 68.26% C) 84.13% D) 56.36% E) 16.87% 26. A confidence interval for the population mean is an interval constructed around the _____. 27. A confidence interval increases in width as A) The level of confidence increases B) n decreases C) s increases D) All of the above 28. For a given hypothesis test, if we do not reject H0 , and H0 is true. A) No error has been committed. C) Type II error has been committed. B) Type I error has been committed. D) Type III error has been committed. 29. If a null hypothesis is rejected at a significance level of .01, it will ______ be rejected at a significance level of .05 A) Always B) Sometimes C) Never 30. If a null hypothesis is rejected at a significance level of .05, it will ______ be rejected at a significance level of .01 A) Always B) Sometimes C) Never 31. If a null hypothesis is not rejected at a significance level of .05, it will ______ rejected it at a significance level of .01 A) Always B) Sometimes C) Never 32. When testing a hypothesis about a single proportion, Z statistic is ___________ used. A) Always B) Sometimes C) Never 33. The dependent variable is the variable that is being described, predicted, or controlled. A) True B) False 34. A simple linear regression model is an equation that describes the straight-line relationship between a dependent variable and an independent variable. A) True B) False 35. The residual is the difference between the observed value of the dependent variable and the predicted value of the dependent variable. A) True B) False 36. The _____ of the simple linear regression model is the value of y when the mean value of x is zero. 37. In simple regression analysis, if the correlation coefficient is a positive value, then A) The Y intercept must also be a positive value. B) The coefficient of determination can be either positive or negative, depending on the value of the slope. C) The least squares regression equation could either have a positive or a negative slope. D) The slope of the regression line must also be positive. E) The standard error of estimate can either have a positive or a negative value. 38. The following results were obtained from a simple regression analysis: y = 37.2895 - 1.2024 X R2 = .6774 s = .2934 For each unit change in X (independent variable), the estimated change in Y (dependent variable) is equal to: A) -1.2024 B) .6774 C) 37.2895 D) .2934 39. Use the previous results to answer: When X (independent variable) is equal to zero, the estimated value of Y (dependent variable) is equal to: A) -1.2024 B) .6774 C) 37.2895 D) .2934 40. Use the previous results to answer: ____________ is the proportion of the variation explained by the simple linear regression model: A) -1.2024 B) .6774 C) 37.2895 D) .2934 41. Consider the following partial computer output from a simple linear regression analysis. Variable Coefficent Std Dev t p Intercept -28.13 -.008 .932 X 1.12 0.049 22.89 .0001 R2 .9722 Find the estimated y-intercept. 42. Using the above partial output: Find the estimated slope. 43. Using the above partial output: Write the equation of the least squares line. 44. Using the above partial output: Find the t statistic and test H0: B1 0 vs. Ha: B1 >0 at =.05. 45. Using the above partial output: Calculate the correlation coefficient. 46. Using the above partial output: What is the predicted value of y when x = 1,000? 47. A control chart is a graph whose purpose is to detect assignable causes of variation in a process. A) True B) False 48. _______ chart monitors the process variation. A) B) R C) C D) P E) Individuals 49. If 20 samples of size 7 are drawn with = 33.33 and = 5.65, what is the UCL and the LCL for the chart? 50. If 20 samples of size 7 are drawn with = 33.33 and = 5.65, what is the UCL and LCL for the R-chart? 51. The statistic from a contingency table with 6 rows and five columns will have A) 30 degrees of freedom D) 20 degrees of freedom B) 24 degrees of freedom E) 25 degrees of freedom C) 5 degrees of freedom 52. Consider the contingency table below. Factor B Factor A B1 B2 A1 16 14 A2 15 25 A3 9 21 Compute the expected frequencies in row 1. 53. Consider the contingency table above. Compute the expected frequencies in row 3. 54. Consider the contingency table above. How many degrees of freedom are associated with the chi-square test? 55. Consider the contingency table above Test H0: the factors A and B are independent at = .05. 56. On the most recent tax cut proposal, a random sample of democrats and republicans in the Congress cast their votes as follows: Tax Cut Proposal Favor Oppose Abstain Democrats 85 78 37 Republicans 118 61 25 Determine the expected frequencies for a chi-square test of independence. 57. Consider the contingency table above determine the appropriate degrees of freedom and the tabular chi-square statistic for this test. 58. Consider the contingency table above Calculate the chi-square statistic for this test of independence (interpret). Answer Key 1. A 2. B 4. B 5. C 6. D 7. B 8. B 9. A 10. A 11. A 12. B 13. Median 14. Right 15. Left 16. C 17. A 18. C 19. A 20. D 21. B 22. B 23. D 24. C 25. C 26. Sample mean 27. D 28. A 29. A 30. B 31. C 32. A 33. A 34. A 35. A 36. y-intercept 37. D 38. A 39. C 40. B 41. -28.13 42. 1.12 43. = -28.13 + 1.12x 44. t=22.895, reject H0 .0001 < .05, reject H0 45. .986 46. 1,091.87 = -28.13 + 1.12(1000) = 1091.87 47. A 48. B 49. 30.963, 35.697 50. 0.429 and 10.871 51. D 52. 12,18 53. 12,18 54. 2 Degrees of freedom = (3 - 1)(2 - 1) = 2 55. Fail to reject H0 56. 100.5, 68.81, 30.69, 102.51, 70.19, 31.31 57. 2, 9.21 58. 9.73