Last August most gasoline stations in the XT chain of gasoline stations participated in a temporary sales promotion that XT sponsored. In the promotion, any customers who purchased ten or more gallons of gasoline were entitled to a free car wash. For the month of August, the XT chain’s gasoline sales were five percent higher than in August the previous year. Evidently the promotion was successful as a means of boosting sales.Conclusion:
Evidently the promotion was successful as a means of boosting sales. Supporting premise:
For the month of August, the XT chain’s gasoline sales were five percent higher than in August the previous year. We see that the reasoning of the argument is basically that, since XT's sales were higher when the promotion was occurring than when it wasn't, the promotion was the cause of the sales increase.
Which of the following, if true, most strengthens the argument?The correct answer to this Strengthen question will help to confirm that the promotion was indeed the cause of the sales increase.
A. During last August, some of XT’s competitors also had sales promotions in effect and also experienced sales increases as compared to the previous August.This choice may seem to confirm that sales promotions were the causes of the sales increases. However, in reality, it makes no difference.
After all, it just extends what we already know - there were promotions and sales increases at the same time - to competitors.
Great, but did the promotions cause the sales increases?
To confirm the connection between the promotions and the sales increases, we need something new.
Eliminate.
B. The money that XT earned from the increase in gasoline sales was not enough to offset the cost of providing free car washes during the promotion.This choice provides only information on the net profitability of the promotion and none on whether the sales increase was actually caused by the promotion.
Eliminate.
C. Some customers who took advantage of the promotion would have made smaller but more frequent gasoline purchases at XT gasoline stations if the promotion had not been in effect.This information may seem to affect the strength of the argument but actually makes no difference at all.
The passage states as fact that sales were 5 percent higher than sales in August of the previous year. So regardless of whether some customers changed their buying patterns in response to the promotion without changing the amount of gasoline they purchased, it remains the case that sales increased by 5 percent.
Eliminate.
D. XT gasoline stations that participated in the promotion but did not have car wash facilities on their premises gave vouchers that could be used at a nearby car wash.This indicates only how the promotion was handled, not whether it caused the increase in sales.
After all, the fact that some stations gave out vouchers doesn't really add to what we know. We already know from the passage that there was a promotion. The fact that vouchers were used for the promotion doesn't connect the promotion to the sales increase.
Eliminate.
E. Last August the XT gasoline stations that did not participate in the promotion had no increase in gasoline sales as compared to their sales the previous August.This choice is interesting.
After all, it shows what happens if we remove the variable of the promotion.
We already know that, with the promotion, sales increased. Now this choice tells us that, without the promotion, sales didn't increase.
In other words, without the presumed cause, there was no effect.
That information provides some confirmation that the sales increase was caused by the promotion.
Keep.
Correct answer: E