HKSM
Histogram
A bar chart that shows how often numeric values fall within continuous ranges (bins), revealing the distribution of the data.
Key Points
- Displays frequency of numerical data grouped into intervals (bins).
- Bars are adjacent to indicate continuous ranges, not separate categories.
- Helps detect shape, spread, central tendency, and outliers in the data.
- Common in quality management to analyze process variation and performance.
Example
A project manager collects cycle times for 150 service tickets and builds a histogram to see how the times are distributed, identify long-tail delays, and set realistic SLAs.
PMP Example Question
Which tool should a project manager use to visualize how frequently defect counts fall within specific ranges for each production batch?
- Histogram
- Pareto chart
- Control chart
- Scatter diagram
Correct Answer: A — Histogram
Explanation: A histogram is a bar chart that shows the frequency distribution of numerical data across intervals, which fits the need to see how often defect counts fall within ranges.
