PrepTest 102, Section 3, Question 18
In the past decade, a decreasing percentage of(67 more words not shown)
Which one of the following,(10 more words not shown)
- AVarieties of disease(13 more words not shown)
- BNonstandard methods of(13 more words not shown)
- COf total medical(16 more words not shown)
- DMost of the(16 more words not shown)
- EThe total amount(13 more words not shown)
Reading the argument
A smaller percentage of what?
Suppose treatment of disease X used to cost $100 in total, and $10 went to standard treatment. That is 10 percent. Now suppose total spending is $1 million and $1,000 goes to standard treatment. Its share has fallen to one-tenth of 1 percent, but the dollars spent on it have increased from $10 to $1,000.
Those are hypothetical numbers, but they show why the opening percentage does not settle the conclusion. The author needs to know how much money is being divided up.
The middle of the passage explains which treatments work. The standard treatments are effective but painful; the nonstandard ones cause little discomfort but do not work. Less discomfort sounds appealing, but it is not the same as treating the disease effectively. Accepting all of that still leaves the money problem: the conclusion says spending on effective treatment has fallen, while the evidence gives a falling share.
What we’re looking for
The question asks us to add something that proves the conclusion. My prediction is that total spending on disease X has stayed the same or decreased. A smaller share of an unchanged or smaller total must be fewer dollars.
Working the answers
- A
Some expensive varieties of the disease becoming less common does not establish how much is spent on treating disease X overall. Other varieties could become more common, or spending on their treatment could rise. This does not give us the total we need to convert the falling percentage into a falling dollar amount.
- B
A treatment becoming more expensive is not the same as a particular total amount being spent on it. We would also need to know how much of that treatment people receive. More importantly, this concerns the nonstandard treatments, while the conclusion concerns dollars going to the effective, standard treatments. Their dollar amount remains unknown.
- C
Now we have another percentage with another total behind it. Disease X could take a larger share of all medical spending while its own dollar amount rises, falls, or stays the same, depending on what happens to total medical spending.
For example, $20 out of $100 is a larger share than $30 out of $300, even though $20 is less money. C does not establish the amount spent on disease X, so it cannot settle the amount spent on its effective treatments.
- D
This tells us where most disease-X spending went over the decade as a whole. It does not compare the total dollars spent at the beginning and end. We already know that nonstandard treatments take an increasing share. Knowing that they also received most of the money over that period does not tell us whether standard-treatment dollars fell.
- ECorrect
Total spending on disease X declined, and the standard treatments received a smaller percentage of that smaller total. Their dollar amount must have declined too.
Think of a smaller slice of a smaller pie. If the pie itself has shrunk, a slice that also takes a smaller share cannot contain more pie. The first example only worked because total spending increased enormously. E rules out that possibility and gives us enough to prove the conclusion.
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