Pre-Algebra
Data and graphs
Dot plots and histograms
20 practice questions
0 video lessons
Theory + worked examples
Dot Plots and Histograms
Common Core Pre-Algebra • Standard 6.SP.4 • Data & Graphs
Dot Plots and Histograms is a topic in Data & Graphs in the Common Core State Standards. It is aligned to Standard 6.SP.4, which requires students to construct and interpret dot plots and histograms.
Dot plots show each data value; histograms group values into intervals with bars.
Theory
A dot plot stacks one dot per data value; a histogram uses bars for the frequency in each interval.
Both show the shape of the distribution — center, spread, and gaps.
A dot plot and a histogram.
Comparing the two.
Frequency:
\[\text{bar height}=\text{count in that interval}\]
Histograms have no gaps between bars.
How to read these displays
- Dot plot: count dots above each value.
- Histogram: read the bar height for each interval.
- Look for the center and spread.
- Note peaks and gaps.
Example 1 — Read a dot plot
If \(4\) has \(4\) dots, how many data points equal \(4\)?
Solution
Count the dots.
| \(4\) |
Example 2 — Histogram bar
What does the height of a histogram bar show?
Solution
The frequency (count) for that interval.
Example 3 — Which for intervals
Which display groups data into ranges?
Solution
A histogram.
Example 4 — Shape
What do both displays reveal?
Solution
The shape of the distribution.
Common pitfalls
Histogram bars touch; bar graphs have gaps.
Each dot is one data point.
Histograms group, dot plots don't.
Frequently asked questions
What is a dot plot?
A display with one dot per data value.
What is a histogram?
A display of frequencies over intervals.
What does bar height show?
The count in that interval.
Do histogram bars touch?
Yes.
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