This question-specific review guide is tied to the answer reasoning for a PracticeTestVault item. Use it after you answer the question so the review stays focused on what the prompt actually tested.
What this question is testing
Objective: Solve problems involving averages
Prompt focus: A student scored 78, 85, and 92 on three tests. What score must the student earn on a fourth test to have an average of exactly 85?
Why the correct answer works
85
Correct. An average of 85 over 4 tests requires a total of 340, and 340 minus the current sum of 255 equals 85.
Why the tempting wrong answer fails
The tempting wrong answer usually loses because it skips the key condition, priority, or evidence in the prompt.
Plain-language takeaway
To find the needed score, multiply the desired average by the total number of tests to get the required total, then subtract the sum of existing scores.
Simple analogy
Think of solve problems involving averages like following a short checklist: identify the clue, confirm the rule, and then make the move that fits this exact scenario.
How to review it before a retake
- Underline the command word and name what the question is asking before rereading the choices.
- Compare the correct answer against the closest distractor and write the exact detail that separates them.
- Retest this objective with a fresh question without looking at the rationale first.