What graphical display uses bars of equal width to show the number of observations in each class?

What graphical display uses bars of equal width to show the number of observations in each class?

• A. Stem-and-leaf display
• B. Relative frequency distributions
• C. Histogram
• D. Mean

Answer: (C)

Histograms display a distribution by grouping data into equal-width intervals (classes) and drawing a bar for each interval whose height represents the number of observations in that interval. The equal width lets you compare frequencies across intervals directly, and when widths are the same, the bar area reflects frequency consistently. A stem-and-leaf plot shows individual data values arranged by value rather than bars, so it isn’t about equal-width bars. Relative frequency distributions can be shown with bars too, but the description about equal-width bars specifically matching “the number of observations in each class” points to a histogram. The mean is just a numeric summary, not a graphical display.

Histograms display a distribution by grouping data into equal-width intervals (classes) and drawing a bar for each interval whose height represents the number of observations in that interval. The equal width lets you compare frequencies across intervals directly, and when widths are the same, the bar area reflects frequency consistently. A stem-and-leaf plot shows individual data values arranged by value rather than bars, so it isn’t about equal-width bars. Relative frequency distributions can be shown with bars too, but the description about equal-width bars specifically matching “the number of observations in each class” points to a histogram. The mean is just a numeric summary, not a graphical display.