PT61.S2.Q23 - every brick house on river street has a front yard

Comments

• nicole.hopkins Inactive Sage Inactive ⭐

  April 2015 7965 karma

  I'm not 100% clear on your question—

  @alexroark5 said:
  Would we still be justified in claiming most brick house front yards have two stories??
  

  My short answer is no ... That's the faulty conclusion this PF/MtF question comes to. Would you clarify what you're asking?
• alexroark5 Alum Member Inactive ⭐

  April 2015 812 karma

  Right, I undestand that its invalid reasoning. But JY equates Most houses on river street have front yards with being the same as most BRICK houses on river street having forn yards. Does that make more sense?
• Luluc1234 Alum Member

  April 2015 edited April 2015 150 karma

  If the argument had said "most BRICK houses on river street with front yards also have two stories," the argument will be valid. The argument starts with information about brick houses: they have front yards. Then, the argument discusses houses with front yards: most have two stories. You draw the "most arrow" from "front yard" to "two stories" because the corresponding premise is about front yard. In other words, an arrow from FY is independent of the arrows to FY.
• alexroark5 Alum Member Inactive ⭐

  April 2015 812 karma

  Let me try to be more clear.
  
  Stimulus:
  
  BHR (Brick houses on river street)
  F (front yard)
  HRF (Houses on river street that have front yards)
  2 (have two stories)
  
  Premise: BRH --> F
  Premise: HRF ---most--> 2
  
  therefore: BRH -most-> 2
  
  JY says this is invalid argument form number 4 but I don't see how we are justified in connecting F --> HRF
  My objection is that BRH and HRF are not the same. No BRH having front yards is consistent with most HRF having front yards.
  
  Correct Answer choice:
  
  L (legislators)
  not R (have not run for office)
  P (public servant)
  
  Premise: L ---> P
  Premise: P --most--> not R
  
  Therefore: L --most--> not R
  
  To me this is very clearly argument form number 4 (A-->B--most--> C therefore A ---most--> C)
• nicole.hopkins Inactive Sage Inactive ⭐

  April 2015 7965 karma

  @alexroark5 said:
  No BRH having front yards is consistent with most HRF having front yards.
  

  Stimulus:
  BH —> FY
  FY -most-> TS
  BH -most-> TS
  
  Form in generic terms:
  A —> B
  B -most-> C
  A -most-> C
  
  AC D [rearranged to match stimulus]:
  L —> PS
  PS -most-> NRO
  L -most-> NRO
  
  I think it's most helpful with the "never run for office" condition in the answer choices to think of them as a characteristic as opposed to a negation of "run for office" (meaning, NRO = C in the generic form).
  
  "No BRH having front yards" makes me wonder if you are thinking of this as a negation?
• nicole.hopkins Inactive Sage Inactive ⭐

  April 2015 7965 karma

  @alexroark5 said:
  Premise: L ---> P
  Premise: P --most--> not R
  
  Therefore: L --most--> not R
  

  Yes, here I see you're saying "not R" — is this the rub?
• blah170blah Alum Inactive ⭐

  April 2015 3545 karma

  Both also have that part to whole problem as well, I would say.
  
  BRH is not the same as houses in general, they are a subset. This is also true in D where all legislators aren't the same as public servants in general, they are one body of people who are public servants (where are the judges, social workers, etc).
• nicole.hopkins Inactive Sage Inactive ⭐

  April 2015 7965 karma

  @blah170blah that's a good point; I think the argument form stands whether you notate the elements as subsets or unique variables—word?
• blah170blah Alum Inactive ⭐

  April 2015 3545 karma

  I agree. I think it's not a point that comes up since all the answer choices follow that same set up.
• 1 Like

  nicole.hopkins Inactive Sage Inactive ⭐

  April 2015 7965 karma

  But it's an important point to clarify—I know I definitely mulled over whether this was a vital distinction on a couple of my attempts at this Q (it was my nemesis for a while).
• blah170blah Alum Inactive ⭐

  April 2015 edited April 2015 3545 karma

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