Curriculum placement
Algebra 1. This describes the skill, not a learner estimate.
Comparing center, spread, and shape
Compare distribution shapes center IQR and standard deviation with outlier context
Problem types
- How an outlier moves the center
- Shape and spread in box plots
- Compare standard deviations
Builds on
- Comparing two data distributions
- Median and spread of signed data · Earlier idea
Median and range of one data set extend to comparing groups, including how outliers move the center.
- Mean and median · Earlier idea
The mean moves toward an outlier and the median does not, which decides which center to report.
- Describing spread and outliers · Earlier idea
The mean absolute deviation extends to the standard deviation, which compares the spread of two data sets.
Leads to
- The normal distribution · Extend the idea
Standard deviations compare spread, and the normal rule uses them to say what fraction of values lie within them.
- Testing a difference by randomization · See it applied
The difference in centers between two groups is the statistic that a randomization test compares with chance.
Related skills
- Reading slope and intercept in context · Related idea
An outlier changes a mean, and it can also change a fitted line, so both are judged with outliers in mind.
- Reading a statistical report critically · Related idea
A report that gives only a mean can hide skew or outliers, which a comparison of summaries reveals.
- Margin of error and what a sample supports · Shared foundations
Open the interactive map to explore lessons and skill connections.