Calculating Average Test Scores

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Sarah took eight math tests over the course of a semester. The table below shows her scores for each test:

Test NumberScore (out of 100)
185
292
378
488
595
683
790
889

 

Sarah's Test Scores 8 math tests over one semester. What is her mean score? Test Number Score (out of 100) 1 85 2 92 3 78 4 88 5 95 6 83 7 90 8 89 Can you find Sarah's average score?

Question

What is Sarah’s average (mean) test score for the semester?

Solution:

To calculate the average (mean) test score, we need to:

  1. Find the sum of all the scores
  2. Divide the sum by the number of tests

Sum of all scores: 85 + 92 + 78 + 88 + 95 + 83 + 90 + 89 = 700

Number of tests: 8

Average score = 700 ÷ 8 = 87.5

Therefore, Sarah’s average test score for the semester is 87.5 out of 100.

Alternative method: We could also think of this as a fair share problem. If we wanted to distribute the total points (700) equally among the 8 tests, we would end up with 87.5 points per test.

Sarah's Test Scores — Solution Sum: 85 + 92 + 78 + 88 + 95 + 83 + 90 + 89 = 700 Mean: 700 ÷ 8 = 87.5 All 8 scores at a glance T1 T2 T3 T4 T5 T6 T7 T8 85 92 78 88 95 83 90 89 low high Total: 700 Tests: 8 Mean score: 700 ÷ 8 = 87.5 out of 100