A study finds a positive correlation between hours of exercise and lung capacity. What does this mean?
- AAs exercise increases, lung capacity tends to decrease
- BAs exercise increases, lung capacity tends to increase
- CThere is no link between the two variables
- DExercise has been proven to cause higher lung capacity
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- Positive means the two variables move in the same direction.
- 两个错误答案已被划掉。剩下的两个中有一个是正确的。
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为什么是这个答案
A positive correlation means both variables tend to rise together. Correlation alone does not prove that one causes the other; a controlled experiment is needed for that.
答案
B · As exercise increases, lung capacity tends to increase