Central Tendency on the SAT

Why the SAT Emphasizes Central Tendency

Central tendency describes a typical value in a data set. The SAT often asks you to compute mean, median, or mode, and then decide which measure is most appropriate.

This lesson shows how to compute each measure, how outliers change the mean, and how to choose the measure that best represents the data in context.

A Simple Definition Unlocks Central Tendency

The mean is the average, the median is the middle value after sorting, and the mode is the most frequent value. Each one answers a slightly different question about the data.

When a data set has extreme outliers, the mean can be misleading because it gets pulled toward the outlier. In those cases, the median is often a better description of what is typical.

Work Through Central Tendency Step by Step

Compute the mean for $62, 70, 70, 78, 90$ and notice how each value contributes.

Use Desmos to Check Central Tendency

Desmos can compute statistics from a list or table quickly. This is useful when the data set is long.

Algebra is faster for small lists, but Desmos saves time on long lists.

Desmos is faster when there are many data points. Algebra is faster when the list is short and the mean or median is easy to compute by hand.

Expert move: Enter the data as a list and use mean(...) or median(...) so you do not waste time on long sets.

Check yourself: Desmos does the arithmetic, but you still must sort for the median and interpret the statistic.

• Desmos features used: list statistics.
• Common mistake: forgetting to sort before finding the median.

Practice Central Tendency with SAT-Style Questions

Compute and interpret central tendency.

Key Takeaways to Remember for Central Tendency

• Mean is the average, median is the middle, mode is most frequent.
• Outliers affect the mean most.
• Desmos is helpful for long data sets.