Tuesday, February 20, 2007

CR Questions 35, 36

35). A medical journal used a questionnaire survey to determine whether a particular change in its format would increase its readership. Sixty-two percent of those who returned the questionnaire supported that change. On the basis of this outcome, the decision was made to introduce the new format.

Which one of the following, if it were determined to be true, would provide the best evidence that the journal's decision will have the desired effect?

(A) Of the readers who received questionnires, 90 percent returned them.
(B) Other journals have based format changes on survey results.
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change.
(D) It was determined that the new format would be less costly than the old format.
(E) Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires.

36). Odysseus answered well when the priests showed him a picture of those who had honored the gods and then escaped shipwreck, and asked him whether he did not now acknowledge the power of the gods—"Yes," he asked, "but where are those pictured who were drowned after their prayers?" And such is the way of all superstitions; wherein humans, having a delight in such vanities, mark the events where they are fulfilled, but where they fail, though this happens much oftener, neglect and pass them by.

Which one of the following contains the error of reasoning described by the author in the passage?

(A) I have discovered that Friday the 13th really is a day of misfortune. Just this past Friday, the 13th, I locked myself out of the house.
(B) Although Napoleon and Alexander the Great were short, Abraham Lincoln and Charles de Gaulle were tall. So short people seek leadership in order to overcome feelings of inferiority.
(C) Every semester for the past 15 years, an average of 10 percent of Ms. Elliot's history students have dropped her course before the exam. So, it seems likely that we can expect 10 percent to drop out this year.
(D) No reliable observer has ever actually seen a yeti. The strongest evidence seems to be some suspicious tracks. So I think this search for a yeti is probably a wild-goose chase.
(E) I cannot trust my lucky shirt any longer. I wore it to the game today and our team lost.

Answers --

35). OA - C

1st premise -- 90% of those who returned the questionnaire were unhappy with the old format.

2nd premise -- 50% of those who returned the questionnaire were happy with the old format.

A - incorrect - 90% of those surveyed does not mean that they subscribe to the journal

E - incorrect - Those who did not like old format could have represented only 1% of the surveyed people and those who liked it, the other 99%. Therefore, the conclusion could have been too largely biased towards those who wanted to keep the old format and thus inconclusive. Conversely, those who did not like the old format could have represented 99% of the surveyed people and those who liked it, the other 1%. In this case, the conclusion could have been too largely biased towards those who did not want to keep the old format. Therefore, E is inconclusive

A quick glance tip - Only C addresses the opinions of non-readers so only C can possibly support the conclusion

36). OA - A

We know if A => B and not B => not A (contrapositive).

The logic in the stem -- if A leads to B, then B must lead to A.
If all the people survived have prayed, then praying must be sure to make you survive. This is logically WRONG. In fact, B (praying) may or may not lead to A (survive). It is the same with choice A. Friday the thirteen may or may not leads to unlucky events even if one unlucky event happened on Friday the thirteenth.

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