Statistical Displays

Algebra 1 · Axiom Academy

One dataset, built five ways — a dot plot, a histogram, a bar chart, a box plot, and a stem-and-leaf plot — so you can see what each picture reveals. A dot plot places one dot above each value on a number line. When a value repeats, its dots stack — so the tallest column marks the most common value. It is the most literal display: every data point is a single visible dot. Books read last month (15 students) For larger or more spread-out data, dots get unwieldy. A histogram groups values into equal-width intervals called bins , then draws a bar whose height is the count in that bin. The bars touch — the axis is a continuous scale, not separate categories. Test scores, out of 100 (12 students) No gaps — the x-axis is one continuous numeric scale. Each bar's height is how many values fell into that bin. Wider bins smooth the shape; narrower bins show more detail. Symmetric, skewed, or multi-peaked — visible at a glance. A bar chart looks like a histogram but answers a different question. Its categories are not numbers on a scale — they are labels, like sports or colors. So the bars have gaps between them, and you may reorder them freely. Use a bar chart whenever the thing on the x-axis is categorical, not measured. Numeric bins on a continuous axis. Bars touch. Order is fixed by value. Named categories. Bars have gaps. Order is yours to choose.

This is the written version of the interactive lesson above. See the full Algebra 1 course.