BUS 322 Data Analysis Final

39. What is the confidence coefficient when the level of significance is 0.03? a. 0.9700 b. 0.0376 c. 0.7924 d. 0.7776

Answer: A

60. Which of the following data patterns best describes the scenario shown in the given time series plot? (imagine a jagged hill climbing to the right) a. Linear trend pattern b. Nonlinear trend pattern c. Seasonal pattern d. Cyclical pattern

Answer: A

13. A summary of data that shows the number of observations in each of several nonoverlapping bins is called a. a frequency distribution. b. a sample summary. c. a bin distribution. d. an observed distribution.

Answer: A Feedback: A frequency distribution is a summary of data that shows the number (frequency) of observations in each of several nonoverlapping classes, typically referred to as bins, when dealing with distributions

30. A two-dimensional graph representing the data using different shades of color to indicate magnitude is called a ______. a. heat map b. bubble chart c. column chart d. pie chart

Answer: A Feedback: A heat map is a two-dimensional graphical representation of data that uses different shades of color to indicate magnitude. Heat maps depend strongly on the use of color to convey information over different areas, across time, or both.

8. The act of collecting data that are representative of the population data is called a. random sampling. b. sample data. c. population sampling. d. applications of business analytics.

Answer: A Feedback: A representative sample can be gathered by random sampling of the population data.

54. _____ is used to test the hypothesis that the values of the regression parameters β1, β2, . . . , βq are all zero. a. An F test b. A t test c. The least squares method d. Extrapolation

Answer: A Feedback: An F test is used to test the hypothesis that the values of the regression parameters β1, β2, . . . , βq are all zero.

20. Any data value with a z-score less than -3 or greater than +3 is treated as a(n) a. outlier. b. usual value. c. whisker. d. z-score value.

Answer: A Feedback: Any data value with a z-score less than -3 or greater than +3 is treated as an outlier.

55. forecast is defined as a(n): a. prediction of future values of a time series. b. quantitative method used when historical data on the variable of interest are either unavailable or not applicable. c. set of observations on a variable measured at successive points in time. d. outcome of a random experiment.

Answer: A Feedback: Forecast is defined as a prediction of future values of a time series.

44. In the graph of the simple linear regression equation, the parameter β1 is the _____ of the regression line. a. slope b. x-intercept c. y-intercept d. end-point

Answer: A Feedback: In the graph of the simple linear regression equation, the parameter β1 is the slope of the regression line

2. ______ helps in constructing a mathematical model to predict the future sales, based on past data. a. Predictive analytics b. Decision analysis c. Prescriptive analytics d. Descriptive analytics

Answer: A Feedback: Predictive analytics consists of techniques that use models constructed from past data to predict the future.

16. The _____ shows the number of data items with values less than or equal to the upper class limit of each class. a. cumulative frequency distribution b. frequency distribution c. percent frequency distribution d. relative frequency distribution

Answer: A Feedback: The cumulative frequency distribution shows the number of data items with values less than or equal to the upper class limit of each class.

65. The moving averages and exponential smoothing methods are appropriate for a time series exhibiting _____. a. horizontal pattern b. cyclical pattern c. trends d. seasonal effects

Answer: A Feedback: The moving averages and exponential smoothing methods are appropriate for a time series exhibiting horizontal pattern.

15. Which of the following are necessary to be determined to define the classes for a frequency distribution with quantitative data? a. Number of nonoverlapping bins, width of each bin, and bin limits b. Width of each bin and bin lower limits c. Number of overlapping bins, width of each bin, and bin upper limits d. Width of each bin and number of bins

Answer: A Feedback: The three steps necessary to define the classes for a frequency distribution with quantitative data are: determine the number of nonoverlapping bins, determine the width of each bin, and determine the bin limits.

51. Which of the following inferences can be drawn from the scatter chart given below? (imagine a chart that looks like a shotgun spray from left to right) a. The residuals have a varying variance. b. The model captures the relationship between the variables accurately. c. The regression model follows the F probability distribution. d. The residual distribution is consistently scattered about zero.

Answer: A Feedback: The variation in the residuals e increases as the value of the independent variable x increases, suggesting that the residuals do not have a constant variance.

48. What would be the value of the sum of squares due to regression (SSR) if the total sum of squares (SST) is 25.32 and the sum of squares due to error (SSE) is 6.89? a. 31.89 b. 19.32 c. 18.43 d. 15.32

Answer: C Feedback: The three quantities are related as SST = SSR + SSE. Substituting the values, we get SSR=18.43.

4. A children's apparel manufacturer used descriptive analytics: a. to present supply chain to managers visually. b. to achieve efficiency in delivery of goods. c. to schedule staff and vehicle for delivery. d. to plan capacity utilization by incorporating the inherent uncertainty in commodities pricing.

Answer: A Feedback: The women's apparel manufacturer has successfully used descriptive analytics to present the status of its supply chain to managers visually.

58. Trend refers to: a. the long-run shift or movement in the time series observable over several periods of time. b. the outcome of a random experiment. c. the recurring patterns observed over successive periods of time. d. the short-run shift or movement in the time series observable at some specific period of time.

Answer: A Feedback: Trend refers to the long-run shift or movement in the time series observable over several periods of time.

43. A linear regression analysis for which any one unit change in the independent variable is assumed to: a. have the same change in the dependent variable. b. have no change in the dependent variable. c. have an inverse effect on the dependent variable d. have a nullifying effect on the dependent variable.

Answer: A Feedback: A regression analysis for which any one unit change in the independent variable is assumed to result in the same change in the dependent variable is referred to as a linear regression.

32. Which of the following propositions describes an existing theory or belief? a. standard deviation b. null hypothesis c. proportion d. alternative hypothesis

Answer: B

34. A manufacturer wishes to determine if the average profit from the sale of his product exceeds $6,710. Which of the following is the appropriate hypothesis test? a. H0: population mean profit from sale > $6,710 vs. H1: population mean profit from sale ≤ $6,710 b. H0: population mean profit from sale ≤ $6,710 vs. H1: population mean profit from sale > $6,710 c. H0: population mean profit from sale < $6,710 vs. H1: population mean profit from sale ≥ $6,710 d. H0: population mean profit from sale ≥ $6,710 vs. H1: population mean profit from sale < $6,710

Answer: B

37. Robin Inc. feared that the average company loss is running beyond $34,000. It initially conducted a hypothesis test on a sample extracted from its database. The hypothesis was formulated as H0: average company loss $34,000 vs. H1: average company loss > $34,000. The test resulted in favor of Robin Inc.'s loss not exceeding $34,000. Detailed study of company accounts later revealed that the average company loss had run up to $37,896. Which of the following errors were made during the hypothesis test? a. Type III error b. Type II error c. Type I error d. Type IV error

Answer: B

38. Type II error occurs when the test: a. correctly fails to reject an actually true null hypothesis. b. incorrectly fails to reject an actually false null hypothesis. c. correctly rejects an actually false null hypothesis. d. incorrectly rejects an actually true null hypothesis.

Answer: B

6. A variable whose values are not known with certainty is called a _____. a. certain variable b. random variable c. constant variable d. decision variable

Answer: B Feedback: A quantity whose values are not known with certainty is called a random variable, or uncertain variable.

19. A _____ determines how far a particular value is from the mean relative to the data set's standard deviation. a. coefficient of variation b. z-score c. variance d. percentile

Answer: B Feedback: A z-score helps us determine how far a particular value is from the mean relative to the data set's standard deviation.

1. ______ encompasses reports, data dashboards, and descriptive statistics to describe the past data. a. Predictive analytics b. Descriptive analytics c. Prescriptive analytics d. Decision analysis

Answer: B Feedback: Descriptive analytics encompasses the set of techniques that describes what has happened in the past.

66. _____ uses a weighted average of past time series values as the forecast. a. The qualitative method b. Exponential smoothing c. Correlation analysis d. The causal model

Answer: B Feedback: Exponential smoothing uses a weighted average of past time series values as the forecast.

3. Which of the following techniques is used in predictive analytics? a. Data dashboards b. Linear regression c. Data visualization d. Optimization models

Answer: B Feedback: Linear regression, time series analysis, some data-mining techniques, and simulation, often referred to as risk analysis, all fall under the banner of predictive analytics.

31. Consider the clustered bar chart of the dashboard developed to monitor the performance of a call center: This chart allows the IT manager to a. identify a particular type of problem by the call volume. b. identify a particular type of problem by location. c. identify different types of problems (Email, Internet, or Software) in the call center. d. identify the frequency of each problem in the call center.

Answer: B Feedback: The clustered bar chart shows the call volume in the call center by type of problem (Email, Internet, or Software) for each of three cities in Texas. This chart allows the IT manager to quickly identify if there is a particular type of problem by location.

50. What would be the coefficient of determination if the total sum of squares (SST) is 23.29 and the sum of squares due to regression (SSR) is 10.03? a. 2.32 b. 0.43 c. 13.26 d. 0.89

Answer: B Feedback: The coefficient of determination r2 = SSR/SST. Substituting the given values we get r2 =0.43.

52. The following scatter chart would help conclude that (imagine the chart looks like a "u"): a. the residuals have a constant variance. b. the model fails to capture the relationship between the variables accurately. c. the model underpredicts the value of the dependent variable for intermediate values of the independent variable. d. the residual is normally distributed.

Answer: B Feedback: The residuals are positive for small and large values of the independent variable x but are negative for the remaining values of the independent variable. This pattern suggests that the linear relationships in the regression model underpredicts the value of dependent variable for small and large values of the independent variable and overpredicts the value of the dependent variable for intermediate values of the independent variable. In this case, the regression model does not adequately capture the relationship between the independent variable x and the dependent variable y.

12. Data collected from several entities over several time periods is a. categorical and quantitative data. b. time series data. c. source data. d. cross-sectional data.

Answer: B Feedback: Time series data are collected over several time periods.

45. When the mean value of the dependent variable is independent of variation in the independent variable, the slope of the regression line is _____. a. positive b. zero c. negative d. infinite

Answer: B Feedback: When the mean value of the dependent variable is independent of the variation in the independent variable, the slope of the regression line is zero.

35. Which of the following is true about determining the proper form of the hypotheses? a. H0 is statistically proved true while testing b. failure to reject H0 proves H1 wrong c. H0 is always assumed to be true in testing d. H1 is always assumed to be true in testing

Answer: C

40. For a one-tailed test, the critical value: a. divides the sampling distribution into three parts. b. is the number of standard errors away from the sample mean. c. helps determine if the test statistic falls in the rejection region or not. d. fails to reject the null hypothesis if the test statistic exceeds the critical value.

Answer: C

29. In order to visualize three variables in two-dimensional graph, we use a a. 2-D chart. b. 3-D chart. c. bubble chart. d. column chart.

Answer: C Feedback: A bubble chart is a graphical means of visualizing three variables in a two-dimensional graph and is therefore, sometimes a preferred alternative to a 3-D graph.

5. A variable is defined as a a. quantity of interest that can take on same values. b. set of values. c. quantity of interest that can take on different values. d. characteristic that takes on same values from a set of values.

Answer: C Feedback: A characteristic or a quantity of interest that can take on different values is known as a variable.

42. A regression analysis involving one independent variable and one dependent variable is referred to as a _____. a. factor analysis b. time series analysis c. simple regression d. data mining

Answer: C Feedback: A regression analysis involving one independent variable and one dependent variable is referred to as a simple regression.

7. _____ act(s) as a representative of the population. a. The analytics b. The variance c. A sample d. The random variables

Answer: C Feedback: A subset of the population is known as a sample, and it acts as a representative of the population

56. A set of observations on a variable measured at successive points in time or over successive periods of a. geometric series b. time invariant set c. time series d. logarithmic series

Answer: C Feedback: A time series is a sequence of observations on a variable measured at successive points in time or over successive periods of time.

11. _____ are collected from several entities at the same point in time. a. Time series data b. Categorical and quantitative data c. Cross-sectional data d. Random data

Answer: C Feedback: Cross-sectional data are collected from several entities at the same, or approximately the same, point in time.

22. Data-ink is the ink used in a table or chart that a. does not help in conveying the data to the audience. b. helps in presenting data when the audience need not know exact values. c. is necessary to convey the meaning of the data to the audience. d. increases the Non-data-ink ratio.

Answer: C Feedback: Data-ink is the ink used in a table or chart that is necessary to convey the meaning of the data to the audience.

64. If the forecasted value of the time series variable for period 2 is 22.5 and the actual value observed for period 2 is 25, what is the forecast error in period 2? a. 3 b. 2 c. 2.5 d. -2.5

Answer: C Feedback: Forecast error is the amount by which the forecasted value differs from the observed value. For the given values, the forecast error in period 2 is computed as 25 - 22.5 = 2.5.

9. The data on grades (A, B, C, and D) scored by all students in a test is an example of a. quantitative data. b. sample data. c. categorical data. d. analytical data.

Answer: C Feedback: If arithmetic operations cannot be performed on the data, they are considered categorical data.

27. If the scatter chart indicates a positive linear relationship between two variables, then their correlation coefficient is a. equal to -1. b. greater than 1. c. between 0 and +1. d. between -1 and 0.

Answer: C Feedback: If the scatter chart indicates a positive linear relationship between two variables, then their covariance is positive and hence, their correlation coefficient is between 0 and +1.

21. The correlation coefficient will always take values a. greater than 0. b. between -1 and 0. c. between -1 and +1. d. less than -1.

Answer: C Feedback: The correlation coefficient will always take values between -1 and +1.

46. The procedure of using sample data to find the estimated regression equation is better known as _____. a. point estimation b. interval estimation c. the least squares method d. extrapolation

Answer: C Feedback: The least squares method is a procedure for using sample data to find the estimated regression equation

23. Tables should be used when a. the reader need not refer to specific numerical values. b. the reader need not make precise comparisons between different values and not just relative comparisons. c. the values being displayed have different units or very different magnitudes. d. the reader need not differentiate the columns and rows.

Answer: C Feedback: The tables should be used when the reader needs to refer to specific numerical values, when the reader needs to make precise comparisons between different values and not just relative comparisons, and when the values being displayed have different units or very different magnitudes.

18. The variance is based on the a. deviation about the median. b. number of variables. c. deviation about the mean. d. correlation in the data.

Answer: C Feedback: The variance is based on the deviation about the mean, which is the difference between the value of each observation (xi) and the mean.

26. A _____ is a line that provides an approximation of the relationship between the variables. a. line chart b. sparkline c. trendline d. gridline

Answer: C Feedback: To obtain an approximate relationship between the variables, we add a trendline on a scatter chart.

24. A useful type of table for describing data of two variables is a a. data table. b. bubble chart. c. crosstabulation. d. scatter chart.

Answer: C Feedback: A crosstabulation provides a tabular summary of data for two variables.

33. Which of the following is a valid one-sample hypothesis test? a. H0: population parameter ≠ constant vs. H1: population parameter = constant b. H0: population parameter > constant vs. H1: population parameter ≤ constant c. H0: population parameter < constant vs. H1: population parameter ≥ constant d. H0: population parameter = constant vs. H1: population parameter ≠ constant

Answer: D

36. Which of the following is a Type I error? a. the null hypothesis is actually true, and the hypothesis test correctly fails to reject it b. the null hypothesis is actually false, but the test incorrectly fails to reject it c. the null hypothesis is actually false, and the test correctly rejects it d. the null hypothesis is actually true, but the hypothesis test incorrectly rejects it

Answer: D

41. For a two-sample hypothesis test for differences in population parameters (1) and (2), which of the following is the correct form of an upper-tailed test? a. H0: population parameter (1) - population parameter (2) ≥ 0 vs. H1: population parameter (1) - population parameter (2) < 0 b. H0: population parameter (1) - population parameter (2) > 0 vs. H1: population parameter (1) - population parameter (2) ≤ 0 c. H0: population parameter (1) - population parameter (2) < 0 vs. H1: population parameter (1) - population parameter (2) > 0 d. H0: population parameter (1) - population parameter (2) ≤ 0 vs. H1: population parameter (1) - population parameter (2) > 0

Answer: D

61. Which of the following data patterns best describes the scenario shown in the given time series plot? (imagine a repeating cycle of data) a. Linear trend pattern b. Logarithmic trend c. Exponential trend d. Seasonal pattern

Answer: D

57. A _____ pattern exists when the data fluctuate randomly around a constant mean over time. a. vertical b. seasonal c. cyclical d. horizontal

Answer: D Feedback: A horizontal pattern exists when the data fluctuate randomly around a constant mean over time.

25. A _____ is a graphical presentation of the relationship between two quantitative variables. a. histogram b. bar chart c. pie chart d. scatter chart

Answer: D Feedback: A scatter chart is a graphical presentation of the relationship between two quantitative variables.

67. Autoregressive models: a. use the average of the most recent data values in the time series as the forecast for the next period. b. are used to smooth out random fluctuations in time series. c. relate a time series to other variables that are believed to explain or cause its behavior. d. occur whenever all the independent variables are previous values of the same time series.

Answer: D Feedback: Autoregressive models occur whenever all the independent variables are previous values of the same time series.

10. The data on the time taken by 10 students in a class to answer a test is an example of a. population data. b. categorical data. c. time series data. d. quantitative data.

Answer: D Feedback: Data are considered quantitative data if numeric and arithmetic operations, such as addition, subtraction, multiplication, and division, can be performed on them.

63. _____ is the amount by which the predicted value differs from the observed value of the time series variable. a. Mean forecast error b. Mean absolute error c. Smoothing constant d. Forecast error

Answer: D Feedback: Forecast error is the amount by which the forecasted value differs from the observed value.

28. A line chart displaying the data values collected over a period of time is termed as a a. boxplot. b. frequency graph. c. dot plot d. time series plot.

Answer: D Feedback: Line charts are very useful for time series data collected over a period of time (minutes, hours, days, years, etc.). Such line charts are often called as time series plots.

47. Prediction of the value of the dependent variable outside the experimental region is called _____. a. interpolation b. forecasting c. averaging d. extrapolation

Answer: D Feedback: Prediction of the value of the dependent variable outside the experimental region is called extrapolation.

49. The coefficient of determination: a. takes values between -1 to +1. b. is equal to zero for a perfect fit. c. is equal to one for the poorest fit. d. is used to evaluate the goodness of fit.

Answer: D Feedback: The coefficient of determination (R-squared) is used to evaluate the goodness of fit for the estimated regression equation.

59. Which of the following data patterns best describes the scenario shown in the below plot? (imagine a mountain range that repeats itself) a. Time series with a linear trend pattern b. Time series with a nonlinear trend pattern c. Time series with no pattern d. Time series with a horizontal pattern

Answer: D Feedback: The given scenario shows a time series plot with a horizontal pattern.

62. Which of the following data patterns best describes the scenario shown in the given time series plot? (imagine a repeating cycle of data that climbs over time) a. Linear trend and cyclical pattern b. Linear trend and horizontal pattern c. Seasonal and cyclical patterns d. Seasonal pattern and linear trend

Answer: D Feedback: The given time series plot exhibits both a seasonal pattern and a linear trend.

14. Compute the relative frequencies for the data given: Grades / Number of students A 16 B 28 C 33 D 13 Total 90 a. 0.31, 0.14, 0.37, 0.18 b. 0.37, 0.14, 0.31, 0.18 c. 0.14, 0.31, 0.37, 0.18 d. 0.18, 0.31, 0.37, 0.14

Answer: D Feedback: The relative frequency of a bin equals the fraction or proportion of items belonging to a class. Relative frequency of a bin = Frequency of the bin /n.

53. Which of the following inferences can be drawn from the scatter chart given below? (Imagine a chart that looks like glitter stuck to a floor, with a couple dots still floating) a. The residuals have a constant variance. b. The model captures the relationship between the variables accurately. c. The model underpredicts the value of the dependent variable for intermediate values of the independent variable. d. The residual distribution is not normally distributed.

Answer: D Feedback: The residuals in the given figure are not symmetrically distributed around zero; many of the negative residuals are relatively close to zero, while the relatively few positive residuals tend to be far from zero. This skewness suggests that the residuals are not normally distributed.

17. The simplest measure of variability is the a. variance. b. standard deviation. c. coefficient of variation. d. range.

Answer: D Feedback: The simplest measure of variability is the range.