Question

Two students in Ms. Smith's class are working on finding the mean for the following set of numbers: 2, 12, 16, 4, 18, 24, 32. Susan states that the answer is 15.4 when rounded to the nearest tenth. She added all of the numbers and divided by 7. Sam disagrees and thinks the answer is 54. She added all of the numbers and divided them by 2. Which student is correct? How do you know? Explain your thinking!

Answer 1

Susan

Explanation:

When finding the mean, you add up all the numbers, and divide by the number of numbers. Since Susan divided by 7 numbers, and there are 7 numbers, we know Susan is right and Sam is wrong.

2 + 12 + 16 + 4 + 18 + 24 + 32 = 108

`(108)/(7)` ≈ 15.4

Susan is right not only by the method, but in the math.