Problem-Solving and Data Analysis practice question

Answer: 2.4 or 12/5

Total books: 1 × 2 + 2 × 4 + 3 × 3 + 5 × 1 = 2 + 8 + 9 + 5 = 24. Total students: 2 + 4 + 3 + 1 = 10. Mean = 24/10 = 2.4.

Common wrong answers

If you answered 6

6 is 24/4, dividing the total by the number of different values instead of by the number of students, 10.

If you answered 24

24 is the total number of books, not the mean per student.

If you answered 2.75

2.75 is the mean of the four VALUES (1, 2, 3, 5) as if each occurred once. Each value must be weighted by how many students it applies to.

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