Chapter 1An Introduction to Business Statistics

True/False

1. A population is a set of existing units. Answer: True Difficulty: Easy

2. If we examine some of the population measurements, we are conducting a census of the population. Answer: False Difficulty: Medium

3. A random sample is selected so that on each selection from the population every unit remaining in the population has an equal chance of being chosen. Answer: True Difficulty: Easy

4. A process is in statistical control if it does not exhibit any unusual variations. Answer: True Difficulty: Easy

5. An example of a quantitative variable is the make of a car. Answer: False Difficulty: Easy

6. An example of a qualitative variable is the mileage of a car. Answer: False Difficulty: Easy

7. Statistical inference is the science of using a sample of measurements to make generalization about the important aspects of a population of measurements. Answer: True Difficulty: Medium

8. If we sample without replacement, we do not place the unit chosen on a particular selection back into the population. Answer: True Difficulty: Medium

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9. By taking a systematic sample, in which we select every 100th shopper arriving at a specific store, we are approximating a random sample of shoppers. Answer: True Difficulty: Medium

10. When beginning a study, we define our variable of interest called a response variable.Answer: True Difficulty: Medium

11. True/False questions are a general type of survey questions.Answer: False Difficulty: Medium

12. Errors of observation are a class of survey error.Answer: True Difficulty: Medium

Multiple Choice

13. Statistical methods help to: A) Demonstrate the need for improvement B) Identify ways to make improvements C) Assess whether or not improvement activities have been successful D) Estimate the benefits of improvement E) All of the above Answer: E Difficulty: Easy (REF)

14. Ratio variable have the following characteristics: A) Meaningful order B) an inherently defined zero value C) Categorical in nature D) Predictable Answer: B Difficulty: Easy

15. When we are choosing a random sample and we do not place chosen units back into the population, we are: A) Sampling with Replacement B) Sampling without Replacement C) Using a Systematic Sample D) Using a Voluntary Response Sample Answer: B Difficulty: Medium (REF)

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16. Which of the following is a quantitative variable? A) The make of a TV B) A person's gender C) Mileage of a car D) Whether a person is a college graduate E) Whether a person has a charge account Answer: C Difficulty: Easy

17. Which of the following is a categorical variable? A) Air Temperature B) Bank Account Balance C) Daily Sales in a Store D) Whether a Person Has a Traffic Violation E) Value of Company Stock Answer: D Difficulty: Medium

18. Measurements from a population are called A) Statistics B) Observations C) Variables D) Processes Answer: B Difficulty: Medium

19. In studying processes, we are interested in examining a characteristic that tells us about the _____ of output. A) Random Sampling B) Statistics C) Variable D) Quality Answer: D Difficulty: Easy (REF)

20. The two types of quantitative variables are: A) Ordinal and ratio B) Interval and ordinal C) Nominative and ordinal D) Interval and ratio E) Nominative and interval Answer: D Difficulty: Medium

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21. Temperature (in degrees Fahrenheit) is an example of a(n) ________ variable. A) Nominative B) Ordinal C) Interval D) Ratio Answer: C Difficulty: Medium

22. Jersey numbers of soccer players is an example of a(n) ___________ variable. A) Nominative B) Ordinal C) Interval D) Ratio Answer: A Difficulty: Medium

23. Weights of items obtained using a well-adjusted scale represents a(n) _____________ level of measurement. A) Nominative B) Ordinal C) Interval D) Ratio Answer: D Difficulty: Medium

24. An identification of police officers by rank would represent a(n) ____________ level of measurement. A) Nominative B) Ordinal C) Interval D) Ratio Answer: B Difficulty: Medium

25. __________ is a necessary component of a runs plotA) Observation over timeB) Qualitative variableC) Random sampling of the dataD) Voluntary response dataAnswer: A Difficulty: Medium

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26. ______________ is the science of using a sample to make generalizations about the important aspects of a population. A) Statistical Process Control B) Descriptive Statistics C) Random sample D) Statistical Inference Answer: D Difficulty: Easy

27. College entrance exam scores, such as SAT scores, are an example of a(n) ________________ variable. A) Ordinal B) Ratio C) Nominative D) Interval Answer: D Difficulty: Hard

28. The number of miles a truck is driven before it is overhauled is an example of a(n) _____________ variable. A) Nominative B) Ordinal C) Interval D) Ratio Answer: C Difficulty: Medium

29. Which one of the following sampling examples would generally lead to the least reliable statistical inferences about the population from which the sample has been selected? A) A random sample selected without replacement. B) A random sample selected with replacement. C) A voluntary response sample D) A systematic sample Answer: C Difficulty: Medium (REF)

30. A(n) ___________________ variable is a qualitative variable such that there is no meaningful ordering or ranking of the categories. A) Ratio B) Ordinal C) Nominative D) Interval Answer: C Difficulty: Easy

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31. A person's telephone area code is an example of a(n) _____________ variable. A) Nominative B) Ordinal C) Interval D) Ratio Answer: A Difficulty: Medium

32. Any characteristic of a population unit is a(n): A) Measurement B) Sample C) Observation D) Variable Answer: D Difficulty: Medium

33. A list of all of the units in a population is called _____. A) Census B) Frame C) A sample D) A variable Answer: A Difficulty: Medium

34. Which of the following is not a type of survey?A) Personal interviewsB) Phone surveysC) Mail surveysD) Mall surveysAnswer: D Difficulty: Easy

35. Which of the following is not a type of survey questions?A) Multiple ChoiceB) PilotC) Open ended D) DichotomousAnswer: B Difficulty: Easy

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Fill-in-the-Blank

36. _______is the differences between the values of the sample statistic and the population parameter.Answer: Sampling error Difficulty: Medium

37. __________ occurs when some population units are excluded from the process of selecting the sample.Answer: Undercoverage Difficulty: Medium

38. ___________ is the entire population of interest to us in a particular study.Answer: Target population Difficulty: Medium

39. If a survey instrument contains personal questions and respondents feel obligated to answer, they may not tell the truth. This is called ____________.Answer: Response bias Difficulty: Hard

40. In order to improve the quality of products and services, we must remove the root causes of process _____. Answer: Variation Difficulty: Medium

41. Any characteristic of a population is called a _____. Answer: Variable Difficulty: Medium

42. The goal of _____ is to stabilize and reduce the amount of process variation. Answer: Statistical Process Control Difficulty: Medium

43. A _____ is an examination of all the units in a population. Answer: Census Difficulty: Easy

44. An _____ study is a study in which we make statistical inferences about a population of existing units. Answer: Enumerative Difficulty: Medium

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45. A _____ is a list of all the units in a population. Answer: Frame Difficulty: Medium

46. The process of assigning a value of a variable to each unit in a population or sample is called _____. Answer: Measurement Difficulty: Medium

47. A ____ is a graph of individual process measurements versus time. Answer: Runs Plot Difficulty: Easy

48. Statistical _____ refers to using a sample of measurements making generalizations about the important aspects of a population. Answer: Inference Difficulty: Easy

49. A _____ is a subset of the units in a population. Answer: Sample Difficulty: Easy

50. A _____ variable can have values that are numbers on the real number line. Answer: Quantitative Difficulty: Medium

51. A sequence of operations that takes inputs and turns them into outputs is a _____. Answer: Process Difficulty: Medium

52. A _____ variable can have values that indicate into which of several segments of a population it belongs. Answer: Qualitative Difficulty: Medium

53. A set of existing units we wish to study is called a _____. Answer: Population Difficulty: Medium

54. _____ refers to describing the important aspects of a set of measurements. Answer: Descriptive statistics Difficulty: Medium

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55. In situations when it is not possible to number all of the units in a population, we often use a _____ sample to approximate a random sample. Answer: Systematic Difficulty: Medium

56. A runs plot with an erratic pattern would indicate that the process is _____. Answer: Out of control Difficulty: Medium

57. If a unit is placed back into the population after being selected for a sample, we are sampling _____ replacement. Answer: With Difficulty: Medium

58. A _____ table is used to help select items for a random sample. Answer: Random number Difficulty: Easy

59. A process that is in statistical control does not necessarily imply that the process is __________ of meeting the customer requirements. Answer: Capable Difficulty: Hard

Essay

60. A consumer's yes/no reply to a survey question is what type of variable? Answer: Qualitative Difficulty: Medium (AS)

61. The change in daily price of a stock is what type of variable? Answer: Quantitative Difficulty: Medium

62. List 2 types of sampling methods. Answer: Random and systematic Difficulty: Medium (AS)

63. In a voluntary response sample, what types of opinions are usually expressed? Answer: Strong/negative Difficulty: Hard

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Use the following information to answer questions 64-66. Suppose that a psychologist is interested in the effect of drinking on short term memory. She divides her subjects into two groups where Group A consumes 4 1oz alcoholic drinks in one hour and Group B does not drink anything. At the end of one hour, the subjects are given a list of words to memorize and then are asked to repeat the words and the number repeated correctly are counted.

64. What is the response variable?Answer: Number of correct words repeated Difficulty: Medium (AS)

65. What are the independent variables?Answer: Drinkers versus Non-drinkers Difficulty: Hard (AS)

66. What type of study is this?Answer: Experimental Difficulty: Hard (AS)

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