At Morris University this semester, most of the sociology majors are taking Introduction to Social Psychology, but mo...

Victoria on July 23, 2020

Hi @tomgbean,

Happy to help!

Let's start by determining the error in reasoning made by the argument.

The stimulus concludes that there must be more sociology majors than psychology majors enrolled in Introduction to Social Psychology.

Why? Because most of the sociology majors are taking the class whereas most of the psychology majors are not.

What is the flaw here? The stimulus assumes that there are more sociology majors than psychology majors based on the fact that most of the sociology majors are taking the class whereas most of the psychology majors are not.

This conclusion mistakenly conflates number and percentage. Correctly drawing this conclusion is entirely dependent on the number of students in each major.

For example, if 90% of sociology majors and 40% of psychology majors are in the class but there are 10 sociology majors and 100 psychology majors, then there would be 9 sociology majors as compared to 40 psychology majors and the conclusion would be incorrect.

I find it can be helpful when answering these questions to write the flaw in an abstract way to make it easier to match to answer choices. What is the error committed in the passage?

Most Xs are in Y. Most Zs are not in Y. Therefore, there must be more Xs than Zs in Y.

We are looking for the answer choice which commits the same error in reasoning.

Answer choice (C) is incorrect because it concludes that there are more local trees in the area based on the proportion of local trees in the arboretum.

There are more Xs than Zs in Y. Therefore, there must be more Xs than Zs in Q.

Answer choice (E) is incorrect because it concludes that there are more houses for sale based on the proportion of photos of houses as compared to condos on the website.

Most Xs are in Y. Most Zs are not in Y. Therefore, there must be more Xs than Zs which exist.

Hope this is helpful! Please let us know if you have any further questions.