SAT · Problem Solving & Data Analysis · Scatterplots, tables, and probability
Question sat-q-00166
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The question
The five values in a data set are 48, 35, 25, 55, 48. What is the mean?
- 211
- 52.8
- 42.2
- 25
Show answer & worked solution
Answer: 42.2
Worked solution. Sum the values: 211. Divide by the number of values (5): 211 / 5 = 42.2.
Why each wrong choice is wrong. A distractor returns the median (middle value), which equals the mean only by coincidence. Another divides by the wrong count.
Test-day tactic. Mean is sum over count. Don't confuse it with median (middle value) or mode (most frequent value).
About this question type
Items ask you to read a value off a scatterplot, to identify the line of best fit, to compute a probability or conditional probability from a two-way table, or to interpret a relative-frequency statement.
You will see a question shaped like this one on roughly every other official SAT form, typically at the back end of the section, where the score gradient is steepest. Treat any miss in this subtopic as a signal to drill the subtopic page before you do another full practice test.