How to answer it
- Compute or estimate each measure before and after the change.
- Remember the median depends only on the middle values.
- Compare the size of each change.
Worked example
An original question in the SAT format, already answered.
SAT MathWorked example
The data set 4, 7, 7, 9, 13 gains one more value, 30.
Which measure of the data set increases the most?
- AMode
- BMedian
- CMean
- DNone of them change
Answer: C. The mean goes from 40 ÷ 5 = 8 to 70 ÷ 6 ≈ 11.7. The median goes from 7 to 8, and the mode stays 7.
The most common trap
Assuming all centers move together. Outliers pull the mean much more than the median.
Practice it
Hourly Prep’s daily sets mix one-variable data with the rest of SAT Math, and send more of it your way when it’s a weak spot. See how the SAT prep plan works, or browse the other SAT skill guides.