gvosough wrote:thirty children acquired a total of 2700 baseball cards. if 16% had fewer than 70 baseball cards and the number of cards per child has a normal dist, what percent of the children had greater than 130 baseball cards?
A)2
B)4
C)14
D)34
E)68
OA: A
What's the source of this question? I have two serious problems with it.
First, I have never heard of nor seen an actual GMAT question that used the phrase "normal distribution"; to the best of my knowledge, test takers are not expected even to know what a normal distribution is, let alone memorize the percent breakdown for one.
Second, even if you know the values for a normal distribution there's a lot of grunt work on the question (using the 2700/30 to calculate the mean, then using the 16% below 70 to calculate the value of one standard deviation, then using the value of one standard deviation to find out how many SDs 130 is from the mean) - way more than can reasonably be expected on even a 770 level GMAT question.
I supposed that once you calculate the mean (90) and see that 130 is substantially further from the mean than is 70 you can very quickly eliminate C, D and E (even without knowing what the figures are for a normal distribution), but unless someone provides anecdotal evidence of seeing a "normal distribution" question on the actual GMAT, I'm going to stick with "ignore this question entirely, it's beyond the scope of the exam".
