People who drink coffee are more likely to develop cancer.
1 answer:
Answer: Age and which people were selected for the sample
Explanation:
The hidden variable, in this case, would be age and type of people that are selected for the sample. For example, people that are having many diseases and doctors told them that coffee can harm their health, are the ones that cannot drink coffee, and if they do they can develop cancer in their body.
It is also depending on the age, too young and too old people should not drink coffee or high caffeine drinks.
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