S92-09

Official Solution:


Last year, of the reported thefts that occurred in shopping malls in Texas, the percentage that took place in digital electronic stores increased by two percent from the year before. Because most thefts do not result in the return of stolen goods, this increase likely resulted in a negative economic impact on these digital electronic stores that was greater than the impact that had been accounted for by their yearly budgets, for stores make predictions about the loss of money due to theft based on the number of thefts they recorded in the previous year.

Which of the following, if true, most seriously weakens the argument given?


A. People who steal and are not caught and forced to return the merchandise are likely to steal again.
B. The percentage of reported thefts in shopping malls in Texas that were from jewelry stores last year also increased.
C. Last year, of the total number of thefts from shopping malls across the United States, the percentage of thefts from shopping malls in Texas was lower than it had been the year before.
D. Merchandise stolen from digital electronics stores is generally more expensive than that stolen from other stores.
E. The number of total thefts that were reported in shopping malls in Texas last year was significantly lower than it has been in a decade.


We are told that the percentage of total Texas mall thefts that took place in digital electronic stores has increased. We are also told that stores make predictions about loss based on the number of previous thefts, and that therefore, the stores may have been written their budgets without preparing for this increase.

There is a very important assumption in this argument. Namely, that the number of thefts that took place in digital electronic stores (in Texas malls) has increased. Knowing that the relative percentage of thefts in digital electronic stores, as opposed to all other stores, has increased, does not necessarily imply that the actual number of thefts in such stores has increased.

Let's look at an example to clarify: if there were 200 total thefts in Texas malls in a year, and 20 of them were in digital electronic stores, then 10 of the thefts were in such stores. If, the next year, 12 of Texas mall thefts were in digital electronic stores (the situation given in the prompt, with a 2 increase), this does not tell us that there were more thefts in digital electronic stores. If there were less overall thefts in malls (100, let's say), then there could be less thefts in digital electronic stores (12 rather than 20). The correct answer will point out this possibility.

Choice A refers to thieves that return to steal again. The argument does not refer to the thieves themselves in any capacity; because it is only the total number of thefts we are interested in, this choice is irrelevant to the situation at hand.

Choice B refers to jewelry stores. The relative percentage of thefts of a different type of store does not affect the overall number of thefts, the fact that is needed to weaken this argument.

Choice C is tempting. It claims that the percentage of thefts in Texas malls is lower than it had been in previous years, relative to the total number of thefts from malls overall. However, this choice is still dealing in percentages and not real numbers, and thus is still wrong. Without knowing the overall number of thefts in malls relative from one year to the next, this choice tells us nothing about the actual number of thefts in Texas malls, or the actual number of thefts in Texas mall electronic stores.

Choice D refers to the expense of the products stolen, relative to that of the products of other stores. This is irrelevant, because the predictions made by the electronic stores would, by definition, take the expense of the stolen products into account. This choice adds no new information and thus cannot weaken the argument.

Choice E refers to the total number of thefts in Texas malls, saying that it was lower than it had been in a decade (which includes the previous year as mentioned in the argument). This choice is correct; if the number of overall Texas mall thefts were lower (100 rather than 200, say), then the relative proportional increase of thefts in electronic stores would not necessarily lead to an increase in the real number of thefts in such stores. Without that real increase, the argument does not hold true.


Answer: E