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The correlation figure for a set of readings comes out as a negative number. What does the sign on its own tell you?
AThe readings cannot be fitted with a line
BOne quantity rises as the other one rises
COne quantity falls as the other one rises
DThe line of best fit passes through zero
Answer & Solution
Correct answer: C. One quantity falls as the other one rises
1. The sign of the correlation figure says which way the relationship runs.
2. A positive figure means the two quantities rise together.
3. A negative figure means one falls while the other rises.
4. How strong that relationship is comes from the size of the figure, not its sign.
5. Option B describes a positive figure, so it reads the sign the wrong way round.
_Source: OpenStax College Algebra (CC BY 4.0), Ch 4 "Linear Functions", section 4.3 Fitting Linear Models to Data_
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