Theo, Ara, Jose, and Dana all got 100 percent on their latest math test. Their scores on the previous six tests are listed. Whose mean test score will increase the most? (1 point) Responses Dana: 68, 74, 83, 80, 81, 82 Dana: 68, 74, 83, 80, 81, 82 Theo: 84, 88, 81, 85, 77, 76 Theo: 84, 88, 81, 85, 77, 76 Ara: 100, 98, 99, 97, 100, 100 Ara: 100, 98, 99, 97, 100, 100 Jose: 91, 93, 97, 96, 96, 96

1 answer

To determine whose mean test score will increase the most after scoring 100 on their latest math test, we need to calculate the mean scores for each individual before and after the test.

Step 1: Calculate mean scores before the new test

Dana's scores: 68, 74, 83, 80, 81, 82
Mean = (68 + 74 + 83 + 80 + 81 + 82) / 6
Mean = 468 / 6 = 78

Theo's scores: 84, 88, 81, 85, 77, 76
Mean = (84 + 88 + 81 + 85 + 77 + 76) / 6
Mean = 491 / 6 ≈ 81.83

Ara's scores: 100, 98, 99, 97, 100, 100
Mean = (100 + 98 + 99 + 97 + 100 + 100) / 6
Mean = 594 / 6 = 99

Jose's scores: 91, 93, 97, 96, 96, 96
Mean = (91 + 93 + 97 + 96 + 96 + 96) / 6
Mean = 569 / 6 ≈ 94.83

Step 2: Calculate mean scores after the new test (with a score of 100)

Dana's new mean:
New scores: 68, 74, 83, 80, 81, 82, 100
Mean = (68 + 74 + 83 + 80 + 81 + 82 + 100) / 7
Mean = 468 + 100 / 7 = 568 / 7 ≈ 81.14

Increase = 81.14 - 78 = 3.14

Theo's new mean:
New scores: 84, 88, 81, 85, 77, 76, 100
Mean = (84 + 88 + 81 + 85 + 77 + 76 + 100) / 7
Mean = 491 + 100 / 7 = 591 / 7 ≈ 84.43

Increase = 84.43 - 81.83 ≈ 2.6

Ara's new mean:
New scores: 100, 98, 99, 97, 100, 100, 100
Mean = (100 + 98 + 99 + 97 + 100 + 100 + 100) / 7
Mean = 594 + 100 / 7 = 694 / 7 ≈ 99.14

Increase = 99.14 - 99 = 0.14

Jose's new mean: New scores: 91, 93, 97, 96, 96, 96, 100
Mean = (91 + 93 + 97 + 96 + 96 + 96 + 100) / 7
Mean = 569 + 100 / 7 = 669 / 7 ≈ 95.57

Increase = 95.57 - 94.83 ≈ 0.74

Step 3: Compare increases

  • Dana: Increase of ≈ 3.14
  • Theo: Increase of ≈ 2.6
  • Ara: Increase of ≈ 0.14
  • Jose: Increase of ≈ 0.74

Conclusion

Dana's mean test score will increase the most after scoring 100 on the latest math test.