Question 1

Which of the following is a key guideline for constructing effective graphs, according to the lecture materials?

Accepted Answer

Label both axes and provide proper headings.

Question 2

A bar graph comparing the number of STEM majors to total enrollment uses human-shaped figures of varying heights and widths, but the heights do not accurately represent the counts. What is the main issue with this graph?

Accepted Answer

The areas and heights of the figures are not in accurate proportion to the data, leading to a misleading visual impression.

Question 3

Why is it important for the vertical axis of a bar graph to start at zero?

Accepted Answer

It ensures that the relative sizes of the bars accurately reflect the differences in the data.

Question 4

A newspaper graph shows sales of two newspapers, with the vertical axis starting at 90,000 instead of zero. The difference between the bars appears much larger than it actually is. What is the misleading aspect of this graph?

Accepted Answer

The missing baseline exaggerates the difference between the two newspapers.

Question 5

A bar graph shows 62% of Democrats and 54% of Republicans agreeing with a court decision, but the vertical axis starts at 50%, making the difference appear much larger. What is the main problem with this graph?

Accepted Answer

The truncated y-axis exaggerates the difference between groups.

Question 6

Which of the following is a common mistake when presenting data with multiple possible answers (such as survey responses where respondents can select more than one option)?

Accepted Answer

Using a pie chart, which can mislead because the total can exceed 100%.

Question 7

A graph about global warming uses only air temperature data from the last 10 years to claim that global warming has stopped. What are two main issues with this approach?

Accepted Answer

The graph uses an inappropriate measure (air temperature only) and too short a time frame to make reliable predictions.

Question 8

Suppose a graph shows the following percentages for health problems: 10% high blood pressure, 15% arthritis, 20% heart disease, 10% diabetes, 10% eye problems, 15% osteoporosis, 10% back problems, and 10% urinary incontinence. What is a likely issue with this graph?

Accepted Answer

The percentages add up to more than 100%, which is misleading if a pie chart is used.

Question 9

Which of the following best describes why overloading a graph with too much data (such as showing cumulative COVID-19 cases for all 50 states on one graph) is problematic?

Accepted Answer

It can overwhelm the reader and make it difficult to interpret trends or differences.

Question 10

A graph shows the financial return of higher education over time, but the y-axis is truncated and the scale is inconsistent. What is the likely effect of these choices?

Accepted Answer

It can mislead viewers into thinking the financial return has changed more dramatically than it actually has.

Question 11

Which of the following is NOT a recommended practice when constructing effective graphs?

Accepted Answer

Use decorative images and 3D effects to make the graph more engaging.

Question 12

A graph is constructed to compare two groups, but the values for one group are much larger than the other. What is a better way to present this data?

Accepted Answer

Use separate graphs or plot relative sizes such as ratios or percentages.

Question 13

Suppose you are presented with a graph that does not include a vertical axis or clear labels. What is the most immediate problem with interpreting this graph?

Accepted Answer

It is impossible to determine the exact values or what is being measured.

Question 14

A graph about newspaper sales uses a vertical axis that starts at $$90,000$$ instead of $$0. If $$The Times sells $$100,000$$ copies and The Daily Telegraph sells $$90,000$$, what percentage difference does the graph exaggerate visually?

Accepted Answer

The graph exaggerates the difference to appear as if The Times sells twice as many copies, when in reality the difference is only $$\frac{100,000 - 90,000}{90,000} 	imes 100\% = 11.1\%.$$

Question 15

If a graph uses the area of shapes (such as human figures) to represent data, but the heights are not proportional to the data values, what mathematical principle is being violated?

Accepted Answer

The principle that area should be proportional to the square of the height, so using height alone can mislead viewers.

Question 16

A graph about global warming uses only land temperature data, ignoring ocean temperatures. Why is this problematic for interpreting global warming trends?

Accepted Answer

Land temperatures are more variable and do not capture the full extent of heat retained by the Earth.

Question 17

Which of the following is a better way to present survey data where respondents can select multiple answers?

Accepted Answer

Use a bar chart to show the percentage of respondents for each answer.

(Lecture 5) Guidelines for Constructing Effective Graphs and Recognizing Misleading Data Visualizations

Study Guide - Practice Questions

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