Bunuel
Despite the relentless pursuit of fitness portrayed by the media, the population of the nation is, on average, plumper than was the population 30 years ago. By 2008, the average adult is 11 pounds heavier than was the average adult in 1978.
Which of the following is an assumption underlying the argument above regarding today's average adult?
(A) Today's average adult is not substantially overweight.
(B) Today's average adult is trying to lose weight.
(C) Today's average adult eats healthier food than did the average adult of the past.
(D) Today's average adult is not older than was the average adult of the past.
(E) Today's average adult is not significantly taller than was the average adult of the past.
Official Explanation
Despite the relentless pursuit of fitness portrayed by the media, the population of the nation is, on average, plumper than was the population 30 years ago. By 2008, the average adult is 11 pounds heavier than was the average adult in 1978.
Which of the following is an assumption underlying the argument above regarding today's average adult?(A) Today's average adult is not substantially overweight.
Incorrect.
To solve this Assumption question, first break down the argument. The second sentence includes hard statistical data so it must be the premise. As for the first sentence, we can only see that it is a conclusion because it relies on the second. Tricky one!
Now ask yourself: the author believes the average adult today is plumper (rounder or fatter) than was the average adult 30 years ago, based on their weight. But what is the missing link? What unfounded connection (assumption) does the author make?
The fact that today's average adult is not substantially overweight is irrelevant to the comparison between the average adult weight today and 30 years ago. Therefore, this is not a necessary assumption to reach the conclusion that today's average adult is plumper.
Did you know the meaning of the word plumper when you answered the question?
Plumpness is not just about weighing more. It is about the ratio of weight to height. To conclude that today's average adult is plumper, the author had to take into consideration both weight and height (a 6 foot tall man weighing 200 pounds in not plumper than a 5 foot tall man weighing 189 pounds - he's just bigger!).
(B) Today's average adult is trying to lose weight.
Incorrect.
This answer choice presents a new premise about today's average adult. It is irrelevant whether this new data supports the conclusion; what you are looking for is the assumption, which should explain how the author drew the conclusion based on the existing premise.
(C) Today's average adult eats healthier food than did the average adult of the past.
Incorrect.
If the author assumed today's average adult eats healthier food, why would the author draw the conclusion that today's average adult is plumper? This answer choice contradicts the conclusion.
(D) Today's average adult is not older than was the average adult of the past.
Incorrect.
This answer choice presents a new premise about today's average adult. It is irrelevant whether this new data supports the conclusion; what you are looking for is the assumption, which should explain how the author drew the conclusion based on the existing premise.
(E) Today's average adult is not significantly taller than was the average adult of the past.
Plumpness is not just about weighing more. It is about the ratio of weight to height. To conclude that today's average adult is plumper, the author had to take into consideration both weight and height (a 6 foot tall man weighing 200 pounds is not plumper than a 5 foot tall man weighing 189 pounds - he's just bigger!). This answer choice presents a necessary assumption linking the premise to the conclusion, because without assuming that the heights are similar, the conclusion that today's average adult is plumper than his counterpart 30 years ago is weakened.