The average normal infant born in the United States weighs between twelve and fourteen pounds at the age of three months. Therefore, if a three-month-old child weighs only ten pounds, its weight gain has been below the United States average.
Which of the following indicates a flaw in the reasoning above?
Option (e)
The evidence on which the conclusion is based concerns only average weight, but the conclusion concerns average weight gain. Because there is not necessarily a connection between an absolute measurement-such as weight-and a rate of increase-such as weight gain-this argument is flawed. The relevant reasoning error is described in E, which is the best answer. Neither of A and D identifies a reasoning error in the passage, since the passage makes no claim that weight is the only relevant measure of infant development in general, and no claim about sufficiency. B and C are consistent with the claims in the passage, and neither identifies a flaw in the argument.