Outliers drag the mean: the SAT math trap

Short answer: One extreme value yanks the mean. The median only cares about the middle, so it barely moves.

The trap, in one question

Tempting answer: Both jump a lot

Correct answer: Mean 4 → about 11.67; median 4 → 4.5

How to spot it in 3 seconds

One extreme value yanks the mean. The median only cares about the middle, so it barely moves.

FAQ

What is the outliers drag the mean trap on the SAT?

Example: The value 50 is added to the data set 2, 3, 4, 5, 6. What happens to the mean and median? The tempting answer is Both jump a lot; the correct answer is Mean 4 → about 11.67; median 4 → 4.5.

How do you avoid the outliers drag the mean trap?

One extreme value yanks the mean. The median only cares about the middle, so it barely moves.

More Math traps

← Up 25%, down 25% is not a wash · Standard deviation is spread, not size →