Argument Validity

1. CheckPoint 1: Argument Validity

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Resources: Ch. 7 and the Answers, Suggestions, and Tips for Triangle Exercises section of
Critical Thinking. Please note: You are not required to complete questions displaying a triangle
symbol.

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Due Date: Day 3 [Individual forum].

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Complete Exercise 7-9 on pp. 236-237 of the text.

Exercise 7-9

Given the premises, discuss whether the conclusion of each argument that follows is (a) true beyond
a reasonable doubt, (b) probably true, or (c) possibly true or possibly false. You should expect
disagreement on these items, but the closer your answers are to your instructor’s, the better.

2. The annual rainfall in California’s north valley averages twenty-three inches. So the rainfall next year
will be twenty-three inches.

I would say this is (c ) possibly true or possibly false. The average is just that, average.
Next year’s rainfall could be more or less. But since they arrived at that number by
taking actual data and averaging it, it is still possible that next year’s rainfall could be
what the author predicted.

3. You expect to get forty miles to the gallon in that? Why, that old wreck has a monster V8; besides, it’s
fifty years old and needs an overhaul.

I will pick (b) probably true. V8’s are most often gas guzzler’s, the vehicle being 50
years old and needing an overhaul lends more proof that the vehicle could not get that
kind of gas mileage. Although it is still possible the speaker is wrong in his conclusion or
his assessments, so I can not say beyond a reasonable doubt.

4. In three of the last four presidential races, the winner of the Iowa Republican primary has not captured
the Republican nomination. Therefore, the winner of the next Iowa Republican primary will not capture the
Republican nomination.

This one is (c ) possibly true or possibly false. Whether or not the last three may not have
captured the nomination actually should have no bearing on the next primary candidate.
Therefore he or she would have equal chances as every other candidate and could still go
either way on his or her own merits.

6. The number of cellular telephones has increased dramatically in each of the past few years. Therefore
there will be even more of them in use this coming year.

This also I would say falls under (c ) possibly true or possibly false. The last three years
of data does not guarantee an increase in the coming year. Any business individual
knows after a few years any product does hit a plateau at some point. Therefore, in the
coming year the number could prove correct or not.

7. Since the graduates of Harvard, Yale, Princeton, and other Ivy League schools generally score higher
on the Graduate Record Examination than students from Central State, it follows that the Ivy League
schools do more toward educating their students than Central State does.

I feel as though this falls under (c ) possibly true or possibly false. Scores alone can
not definitively say that school A is more active than school B to helping educate their
students. So, this statement could be true or false.

8. Michael Jackson has had more plastic surgery than anybody else in California. You can bet he’s had
more than anybody in Connecticut!

Since California has more individuals than Connecticut, and assuming this statement is
actually factual I would say this could be (b) probably true.

10. When liquor was banned in 1920, hospitalizations for alcoholism and related diseases plummeted;
in 1933, when Prohibition was repealed, alcohol-related illnesses rose sharply again. Legalization of
cocaine, heroin, and marijuana would not curb abuse of those substances.

I believe this is the one statement I would label (a) true beyond a reasonable doubt. Not
only for the statement made, but the unspoken agreement most professionals have about
dependency to drugs. Legalization does nothing to curb someone’s need for a certain
drug. Therefore I can agree beyond a reasonable doubt that legalization would not curb
abuse of these substances.

11. Relax. The kid’s been delivering the paper for, how long? Three, four years maybe? And not once has
she missed us. The paper will be here, just wait and see. She’s just been delayed for some reason.

This statement I would say is (b) probably true. The speaker has compelling evidence
that his statement is most likely true. There is a slim chance he is not correct in his
assumption, and if so, most likely without his knowledge.