Logical Reasoning

PT120 · S3 · Q1 Although fiber-optic telephone cable

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Although fiber-optic telephone cable is more expensive to manufacture than copper telephone cable, a telephone network using fiber-optic cable is less expensive overall than a telephone network using copper cable.

Statements

pivot / math-y (although, >, <)

MANUFACTURING Fiber-optic > copper $

OVERALL COST OF NETWORK Fiber-optic < copper $

causal (this is because)

Fiber optic is cheaper than copper, to run your network on, because cooper requires frequent amplification, whereas fiber optic can go for a while without needing amplification.

Evaluate

We can tell from the mathematical comparison in the first sentence that other aspects of running a fiber-optic network outweigh the extra cost you pay to manufacture the fiber-optic cable, since a fiber-optic network is cheaper overall than a copper network. Then the second sentence tells us,

When we see Causal Connector Language like , there is a very strong likelihood that the correct answer wants to test us on whether we understand this causal connection.

The order of these statements is "Effect. This is because Cause". So we want to restate this relationship in our more intuitive ordering of Cause leads to Effect.

The fact that copper requires frequent amplification leads to copper being a more expensive cable to run a network off of, despite the fact that copper is cheaper to manufacture than is fiber optic cable.

Goal

Let's look for a safely worded answer that potentially reinforces this idea that

1.

The above statements, if true, most strongly support which one of the following?

  1. The material from which fiber-optic

    Too Speculative

    This answer is attempting to explain why fiber-optic is more expensive to manufacture than is copper. But it might have nothing to do with more expensive materials. Maybe it's a more laborious manufacturing process so it's pricier because it takes longer to make. We shouldn't be speculating the backstory of the facts we're reading. We want to find an answer that's more or less provably true based on the facts we do possess.

    4% picked this

  2. The increase in the number

    Out of Scope: # of transmissions

    We don't have any information about any current increase in the number of transmissions, nor do we get any sense that any network is straining.

    1% picked this

  3. Fiber-optic cable can carry many

    Out of Scope: carry more signals

    Nothing in the passage gets into comparing how many signals each type of network can carry at any given time.

    4% picked this

  4. Signals transmitted through fiber-optic cable

    Out of Scope

    Out of Scope: speed of transmission Too Strong: same The passage never compared the speed at which signals travel, so we have no way to derive the extreme claim that both signals travel as the same speed.

    1% picked this

  5. Correct

    The cost associated with frequent

    Why this is right

    We were told that copper is cheaper than fiber-optic to produce, but a network based on copper cable is more expensive overall, because on the copper network you have to frequently amplify the signal. So that implies that the extra money you have to spend on amplification outweighs the money you saved on the cheaper cable.

    Skill tested: Most Supported · how this choice captures the argument's function is the move to repeat next time.

    90% picked this

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