Which chart type is used to display the distribution of a single variable?

Which chart type is used to display the distribution of a single variable?

• A. Control Chart
• B. Run Chart
• C. Histogram
• D. Pareto Chart

Answer: (C)

A histogram is the chart that shows how a single numeric variable is distributed. It does this by grouping data into bins along the horizontal axis and using bar height to represent how many observations fall into each bin (or the proportion, if you prefer relative frequency). This setup lets you see the overall shape of the data: where values cluster, whether the distribution is symmetric or skewed, if there are multiple peaks, and whether outliers sit at the extremes. Other charts pull in different directions. A control chart monitors a measurement over time to detect process variation, not the distribution of a single variable. A run chart also tracks a value over time to identify trends or patterns, again time-based rather than distribution-focused. A Pareto chart displays categories in order of frequency or impact, which is for categorical data, not a numeric variable’s distribution. So for understanding how one numeric variable is spread across its range, a histogram is the best choice. For example, you might use a histogram to see how exam scores are distributed across the grade spectrum, revealing whether scores form a normal-looking curve, are skewed high or low, or show multiple clusters.

A histogram is the chart that shows how a single numeric variable is distributed. It does this by grouping data into bins along the horizontal axis and using bar height to represent how many observations fall into each bin (or the proportion, if you prefer relative frequency). This setup lets you see the overall shape of the data: where values cluster, whether the distribution is symmetric or skewed, if there are multiple peaks, and whether outliers sit at the extremes.

Other charts pull in different directions. A control chart monitors a measurement over time to detect process variation, not the distribution of a single variable. A run chart also tracks a value over time to identify trends or patterns, again time-based rather than distribution-focused. A Pareto chart displays categories in order of frequency or impact, which is for categorical data, not a numeric variable’s distribution.

So for understanding how one numeric variable is spread across its range, a histogram is the best choice. For example, you might use a histogram to see how exam scores are distributed across the grade spectrum, revealing whether scores form a normal-looking curve, are skewed high or low, or show multiple clusters.