Deck 3: Describing Data Visually

Question 1

Stacked dot plots are useful in understanding the association between two paired quantitative variables (X,Y).

Answer 1

False

Question 2

Compared to a dot plot,we lose some detail when we present data in a frequency distribution.

Answer 2

True

Question 3

Pie charts are useful in displaying frequencies that sum to a total.

Answer 3

True

Question 4

Sturges' Rule should override judgment about the "right" number of histogram bins.

Question 5

Sturges' Rule is merely a suggestion,not an ironclad requirement.

Question 6

Dot plots are similar to histograms with many bins (classes).

Question 7

The line chart is appropriate for categorical (qualitative)data.

Question 8

Dot plots may not reveal the shape of a distribution when the sample is small.

Question 9

Scatter plots are used to visualize association in samples of paired data (X,Y).

Question 10

Excel's pyramid chart is generally preferred to a bar chart.

Question 11

Log scales are common because most people are familiar with them.

Question 12

Pie charts are attractive to statisticians,but are rarely used in business or general media.

Question 13

A bar chart can sometimes be used instead of a line chart for time series data.

Question 14

The Pareto chart is used to display the "vital few" causes of problems.

Question 15

A pie chart can generally be used instead of a bar chart.

Question 16

Excel's 3D pie charts are usually clearer than 2D pie charts.

Question 17

The column chart should be avoided if you are plotting time series data.

Question 18

A common error with pie charts is using too few "slices."

Question 19

Excel's pyramid charts make it easier to read the data values.

Question 20

It is easier to read the data values on a 3D column chart than on a 2D column chart.

Question 21

Which criterion is least likely to be used in choosing bins (classes)in a frequency distribution?

A) Following Sturges' Rule
B) Selecting "nice" class (bin)limits
C) Using aesthetic judgment
D) Always starting at zero

Question 22

A line chart would not be suitable to display which data?

A) U.S.oil imports from OPEC nations for the last 20 years
B) Annual compensation of the top 50 CEOs
C) Exxon-Mobil's quarterly sales data for the last five years
D) Daily stock market closing prices of Microsoft for the past month

Question 23

Which of the following is true?

A) Line charts are not used for cross-sectional data.
B) Line charts are useful for visualizing categorical data.
C) Pyramid charts are generally preferred to bar charts.
D) Pie charts can generally be used instead of bar charts.

Question 24

Except for the Y-axis scaling,a histogram will look the same if we use relative frequencies instead of raw frequencies (with the same bin limits).

Question 25

Which is not a characteristic of a dot plot?

A) Simplicity
B) Legibility
C) Wide bins
D) Dot stacking

Question 26

A frequency distribution is a tabulation of n data values into classes called bins.

Question 27

Line charts are not used for cross-sectional data.

Question 28

The zero origin rule may be waived for bar charts if the objective is merely to visualize relative change over time.

Question 29

A column chart would be least suitable to display which data?

A) Annual compensation of 500 company CEOs
B) U.S.exports to its six largest trading partners
C) Exxon-Mobil's quarterly sales for the last four years
D) One-year CD interest rates paid by the eight largest U.S.banks

Question 30

A frequency distribution usually has equal bin widths.

Question 31

A dot plot would be useful in visualizing scores on an exam in a class of 30 students.

Question 32

A scatter plot is useful in visualizing trends over time.

Question 33

In a bimodal histogram,the two highest bars will have the same height.

Question 34

Which display is most likely to reveal association between X and Y?

A) Dot plot
B) Scatter plot
C) Histogram
D) Pareto chart

Question 35

It is possible to construct a histogram or frequency polygon with open-ended classes.

Question 36

A scatter plot requires two quantitative variables (i.e. ,not categorical data).

Question 37

The ______________ can be used to differentiate the "vital few" causes of quality problems from the "trivial many" causes of quality problems.

A) histogram
B) scatter plot
C) Pareto chart
D) box plot

Question 38

The number of bins in this histogram (caffeine content in mg/oz for 65 soft drinks)is consistent with Sturges' Rule.

Question 39

Histograms generally do not reveal the:

A) exact data range.
B) modal classes (bins).
C) degree of skewness.
D) relative frequencies.

Question 40

Because most data values are on the left,we would say that this dot plot (burglary rates per 100,000 persons in 350 U.S.cities)shows a distribution that is skewed to the left (negatively skewed).

Question 41

Which is not a characteristic of an effective summary table?

A) The main point should be clear within 10 seconds.
B) Data to be compared should be displayed in rows,not columns.
C) Data should be rounded to three or four significant digits.
D) Use space instead of lines to separate columns.

Question 42

Which is not a tip for effective line charts?

A) Line charts are better than bar charts to display cross-sectional data.
B) Numerical labels are omitted on a line chart if there are many data values.
C) Omit data markers (e.g. ,squares,triangles)when there are many data values.
D) Thick lines make it harder to see exact data values.

Question 43

Which of the following is least useful in visualizing categorical data?

A) Bar chart
B) Pie chart
C) Line chart
D) Pareto chart

Question 44

Which is a reason for using a log scale for time series data?

A) It helps compare growth in time series of dissimilar magnitude.
B) General business audiences find it easier to interpret a log scale.
C) On a log scale,equal distances represent equal dollar amounts.
D) The axis labels are usually easier to read in log units.

Question 45

Which data would be suitable for a pie chart?

A) Average starting salary of MBA graduates from six ivy-league universities
B) APR interest rates charged by the top five U.S.credit cards
C) Last semester's average GPA for students in seven majors in a business school
D) The number of U.S.primary care clinics by type (urban,suburban,rural)

Question 46

Scatter plots are:

A) useful in visualizing trends over time.
B) useful in identifying causal relationships.
C) often fitted with a linear equation in Excel.
D) applicable mainly to discrete data.

Question 47

Which is the most serious deceptive graphical technique?

A) Vague source
B) Using bold colors
C) Nonzero origin
D) Unlabeled data points

Question 48

Pivot tables:

A) are similar in purpose to simple 2D pie charts.
B) show how the data "pivot" around a point.
C) show cross-tabulations of data.
D) are not really tables at all.

Question 49

We would use a pivot table to:

A) cross-tabulate frequencies of occurrence of two variables.
B) rotate the data around a central point.
C) establish cause-and-effect between X and Y.
D) display the data in a 3D scatter plot.

Question 50

Which is considered a novelty chart in Excel?

A) Pie chart
B) Column chart
C) Pyramid chart
D) Line chart

Question 51

Which data would be suitable for a pie chart?

A) Percent vote in the last election by party (Democrat,Republican,Other)
B) Retail prices of six major brands of color laser printers
C) Labor cost per vehicle for 10 major world automakers
D) Prices paid by 10 students for their accounting textbooks

Question 52

Effective summary tables generally:

A) have very detailed column headings and footnotes.
B) round their data to three or four significant digits.
C) use plenty of heavy vertical lines to separate the columns.
D) have the raw data listed in a footnote for clarity.

Question 53

Which is not a tip for effective column charts?

A) Time usually goes on the horizontal axis.
B) Bar height should be proportional to the quantity displayed.
C) Label data values at the top of each bar unless graphing lots of data.
D) The nonzero origin rule may be waived for financial reports.

Question 54

Excel's pyramid charts:

A) are generally preferred to pie charts.
B) should be avoided despite their visual appeal.
C) are generally preferred to line charts.
D) show trends more clearly than column charts.

Question 55

Which data would be suitable for a pie chart?

A) Whirlpool Corporation's sales revenue for the last five years
B) Oxnard University student category (undergraduate,masters,doctoral)
C) Average SAT scores for entering freshmen at 10 major U.S.universities
D) U.S.toy imports from China over the past decade

Question 56

Which is a not a characteristic of pie charts?

A) Pie charts can only convey a general idea of the data values.
B) Pie charts are ineffective when they have too many slices.
C) Exploded and 3-D pie charts will allow more "slices."
D) Pie chart data always represent parts of a whole (e.g. ,market share).

Question 57

Which is not considered a deceptive graphical technique?

A) Undefined units
B) 2D graphs
C) Authority figures
D) Distracting pictures

Question 58

Which is not a poor graphing technique?

A) Gratuitous pictures
B) Labeled axis scales
C) 3D bar charts
D) Rotated axis

Question 59

Which is not a reason why pie charts are popular in business?

A) They can convey a general idea of the data to a nontechnical audience.
B) They can display major changes in parts of a whole (e.g. ,market share).
C) They are more precise than line charts,despite their low visual impact.
D) They can be labeled with data values to facilitate interpretation.

Question 60

Which is not considered a deceptive graphical technique?

A) Nonzero origin
B) Elastic graph proportions
C) Dramatic title
D) Axis demarcations

Question 61

Which is not a characteristic of a log scale for time series data?

A) Log scales are useful when data change by an order of magnitude.
B) The distance from 5 to 50 is the same as the distance from 50 to 500.
C) On a log scale,equal distances represent equal ratios.
D) Log scales are generally familiar to the average reader.

Question 62

To classify prices from 62 recent home sales,Sturges' Rule would recommend:

A) 7 classes.
B) 8 classes.
C) 9 classes.
D) 10 classes.

Question 63

Which of these deficiencies would be considered a major graphical deception?

A) Vague or unclear source
B) Using more than one color or font
C) Bar widths proportional to bar height
D) Using a dramatic graph title

Question 64

If you have 32 data points,how many classes (bins)would Sturges' Rule suggest?

A) 5
B) 6
C) 7
D) 8

Question 65

The distribution pictured below is:

A) bimodal and skewed right.
B) bimodal and skewed left.
C) skewed right.
D) skewed left.

Question 66

A histogram can be defined as:

A) a chart whose bar widths show the cumulative frequencies of data values.
B) a chart whose bar widths indicate class intervals and whose areas indicate frequencies.
C) a chart whose bar widths show class intervals and whose heights indicate frequencies.
D) a chart whose bar heights represent the value of each data point.

Question 67

The width of a class in a frequency distribution is known as the:

A) midpoint.
B) class limit.
C) bin frequency.
D) class interval.

Question 68

The graph below illustrates which deceptive technique?

A) Poor Y axis scale
B) Area trick
C) Unclear grid lines
D) Dramatic title

Question 69

Below is a frequency distribution of earnings of 50 contractors in a country. Regarding this distribution,which of the following is correct?

A) The frequency distribution contains too many class intervals.
B) The class interval limits are ambiguous.
C) Too few classes were chosen.
D) The class intervals are too wide.

Question 70

This histogram shows Chris's golf scores in his last 77 rounds at Devil's Ridge.Which is not a correct statement?

A) The number of bins is consistent with Sturges' Rule.
B) The histogram has a noticeable bimodal shape.
C) The modal class is 78 < 80.
D) About 15 percent of his scores are in the interval 74 < 76.

Question 71

If you have 256 data points,how many classes (bins)would Sturges' Rule suggest?

A) 6
B) 7
C) 8
D) 9

Question 72

Bob found an error in the following frequency distribution.What is it?

A) The class limits are overlapping too much.
B) The classes are not collectively exhaustive.
C) There are too many classes by Sturges' Rule.
D) The first class must start at 0.

Question 73

An open-ended bin (e.g. ,"50 and over")might be seen in a frequency distribution when:

A) some data values are not integers.
B) data values are non-numerical.
C) extremely large data values exist.
D) some data are missing.

Question 74

The distribution pictured below is:

A) bimodal and skewed right.
B) bimodal and skewed left.
C) skewed right.
D) skewed left.

Question 75

Which is not a characteristic of using a log scale to display time series data?

A) A log scale helps if we are comparing changes in two time series of dissimilar magnitude.
B) General business audiences find it easier to interpret a log scale.
C) If you display data on a log scale,equal distances represent equal ratios.

Question 76

Which is a characteristic of a histogram's bars?

A) The bar widths reveal the cumulative frequencies of data values.
B) The bar widths indicate class intervals and their areas indicate frequencies.
C) The bar widths show class intervals and their heights indicate frequencies.
D) The bar widths are an exact multiple of the sample size.

Question 77

Which statement is not true concerning Sturges' Rule?

A) It proposes adding one class (bin)to the histogram for each extra observation.
B) If you double the sample size,you should add one class.
C) Its purpose is to tell how many classes (bins)to use in a frequency distribution.
D) It is only a guideline and may be overruled by other considerations.

Question 78

Which is not revealed on a scatter plot?

A) Pairs of observed (x_i,y_i)data values
B) Nonlinear relationships between X and Y
C) Missing data values due to nonresponses
D) Unusual data values (outliers)

Question 79

When using a dot plot with a small sample,which is least apparent?

A) Dispersion of data values within the array
B) The overall shape of the distribution
C) Central tendency of data in the data set
D) Location of data values within the array

Question 80

The point halfway between the bin limits in a frequency distribution is known as the:

A) bin midpoint.
B) bin limit.
C) bin frequency.
D) bin width.