Algebra and Up:
Question: Steven uses the equatino below to find the average change in weight by his dogs after a month of feeding them Such Healthy Very Dog Wow brand dog food.
(2 – 3 + 1 + 5 + 4 + 6) ÷ 8 = x
What is the data set demonstrated by the equation?
Answer: [–3, 0, 0, 1, 2, 4, 5, 6]
Solution: When we find an average of a set, we add up all the values in the set and divide the sum by the number of values. The data set therefore includes all the numbers in the numerator above. But hang on! We're dividing by 8, but there are 6 values added together. That means that there must have been two additional dogs whose weight loss was 0 because Steven could have skipped them in his equation and the average would not change.