Logical reasoning PrepTest 121 · Section 4 · Question 10

Incorrect. The argument doesn't assume a specific motive behind the competitors making their arguments against the plant proposal, so this answer stating that there's a monetary reason for it is incorrect. While that's one potential motive, there are other reasons that the competitors might not want the coal plant to be approved.

Incorrect. This answer reverses the assumption of the argument. There, a group having a vested interest is assumed to establish that they have made a bad argument; this answer states the opposite.

Incorrect. In discussing those supplying fuel to the plants, this answer brings up groups that are out of scope.

Incorrect. The stimulus doesn't establish that good arguments have been made for the proposal, just that no bad arguments have been made against it.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
The arguments against the new coal-burning plant were all made by competitors, so no good arguments have been made against it, so the plant should be approved.

Answer Anticipation:
This argument features a premise/intermediate conclusion/main point structure, albeit in reverse order. It opens with a recommendation ("should") that it immediately backs up with a premise ("since"). It then supports that premise ("After all"), making it an intermediate conclusion. Whenever there's an intermediate conclusion in a flaw-based question, we need to consider potential assumptions in each step of the argument.

Let's start with the premise/intermediate conclusion part of the argument. Does it have to be true that an argument made against a proposal by competitors is a bad argument? Not at all—these competitors do have a bias here, but that doesn't mean that they're wrong. The argument assumes that a biased individual/organization can't make a good argument against something.

Next, let's consider the intermediate conclusion and main point. Does the fact that no good arguments have been made against a proposal mean that the proposal should be accepted? Again, not at all! It could be the case that no good arguments to carry out the proposal have been made, either, or that there is a great argument against it that hasn't been made yet. So this argument is also assuming that a proposal that hasn't been successfully argued against should be approved (an absence of evidence flaw).

Answer Explanation:
This answer states the assumption made between the premise and intermediate conclusion. The argument relies on the bias of the competitors to establish that their arguments against the proposal are bad. If arguments made by those with a vested interest can be good arguments, then the argument falls apart, so this is a necessary assumption.

Key Takeaway:
Arguments with intermediate conclusions have two places to look for assumptions—between premises and the intermediate conclusion, and between the intermediate conclusion and main point. Failing to look for assumptions in both locations will frequently lead you to miss the relevant gap!