Histogram
Each bar represents a numerical interval and its area represents frequency or relative frequency; unequal interval widths require appropriate frequency-density heights. Bars usually touch because intervals are continuous. Inspect bin width, scale, missing values and sample size when interpreting shape, skewness or outliers; a histogram does not show individual causal relationships.
Worked example
Invoice amounts are grouped into equal $100 intervals. Bars for $0–$100 and $100–$200 show 20 and 35 invoices respectively; their heights represent those counts because widths are equal.
Common mistake
Comparing the heights of unequal-width bins as if they directly represented counts, or using separate category bars as though they were a histogram.
Where it appears in your exams
| Qualification | Exam | Relationship | Period |
|---|---|---|---|
| ACCA | MA | Supporting | September 2026–June 2027 |
| FIA | FMA | Supporting | September 2026–June 2027 |