Question

1. which one of the following statements about graphical displays is correct?

a. a pie chart is most effective when the goal is to display how a quantitative variable changes over time.
b. in a bar graph, all bars should have the same width in order to ensure a fair visual comparison across categories.
c. a histogram is appropriate for categorical data because the categories can be arranged side - by - side, with no gaps.
d. in a bar graph, the height of the bars should reflect percentages, but the width of the bars can vary depending on the size of the sample.
e. a line graph should be used if the goal is to determine whether a variable is skewed to the left or skewed to the right.

Explanation:

• Option A: Pie - charts are for showing proportions of a whole, not change over time.
• Option B: In bar - graphs, equal bar widths ensure fair visual comparison among categories, which is correct.
• Option C: Histograms are for numerical data grouped into intervals, not categorical data.
• Option D: In bar - graphs, bar height represents values (not just percentages), and bar widths should be equal.
• Option E: Line graphs are for showing trends over time, not skewness.

Answer:

B. In a bar graph, all bars should have the same width in order to ensure a fair visual comparison across categories.