Problem 2 of 25sta-002
Priya scored 92, 85, 94, and 89 on her first four tests. What score on the fifth test would make the mean of all five tests exactly 88?
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Solution walkthrough1:49
- A mean fixes the total: total mean count. Find the total needed, then what is missing.
- Five tests with a mean of must total points.
- The four known scores total points.
- The fifth test must supply the rest: .
- Check: the four scores sit , , , from , a surplus of . The fifth must be below.
- Traps: is the mean of the first four, is the target itself, and averages with one score.