In one study of a particular plant species, 70 percent of the plants studied were reported as having patterned stems....

odsimkins on July 9, 2020

Can you explain why C is incorrect?

I get how D makes sense as the answer, but I can't quite figure out how to eliminate C. Can you please explain?

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shunhe on July 9, 2020

Hi @odsimkins,

Thanks for the question! So (C) tells us that the second study included about 15% more individual plants than the first study did; in other words, it just tells us that the second study had a higher absolute number of plants. But the total number of plants being measured shouldn’t have an effect on the proportion of plants that have patterned stems, since there’s no reason to assume that the 15% of plants added would have been unrepresentative of the sample as a whole. So adding another representative sample would keep the proportions the same and wouldn’t explain anything, which is why (C) isn’t correct.

Hope this helps! Feel free to ask any other questions that you might have.