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GRE Exam
A certain company made neither a profit nor a loss on the first 1.000 widgets it sold and made a profit of $0.50 on each widget it sold after the first 1.000. If the company's total profit from the sale of widgets was p dollars, what is the number of widgets it sold in terms of p ?
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B)

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E)

Exhibit.

The variance of n numerical data x1, x2, x3, , , , , xn with the mean x is equal to
were S is the sum of the equal differences
for 
For the shares of stock purchased and then sold by the investors shown, the mean of the 5 numbers for Stock Y is 50 and the corresponding mean for Stock X is 70. The variance of the 5 numbers for Stock }' is what fraction of the corresponding variance for Stock X ?
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B)

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D)

E)

Larvae of many marine invertebrate species delay their metamorphosis into juveniles when cues signaling an appropriate juvenile environment are absent, thereby increasing their likelihood of thriving as juveniles and of ultimately reaching adulthood Nevertheless, delayed metamorphosis has potential costs for juveniles including reduced growth and increased mortality Nearly all evidence of such costs involves species whose larvae do not feed but rather subsist on stored nutrients, indicating that insufficient energy reserves may be an underlying cause of these costs. Supporting this hypothesis are laboratory studies showing that in a certain bryozoan. the prolonged larval swimming that results from delayed metamorphosis is associated with size reductions in the juvenile feeding organ (the lophophore) and that one factor influencing the size of juveniles of certain barnacle species is how long larvae delay metamorphosis However, other studies show that while significantly fewer juvenile Capitella worms survived to adulthood when metamorphosis had been delayed, prolonged larval swimming had no significant effect on juvenile size, suggesting, perhaps, that in some species, factors other than insufficient energy reserves account for the negative effects of the larval stresses that result from delayed metamorphosis.
The passage suggests that the, "bryozoan." the "barnacle species.'" and 'Capitella worms" all share which of the following characteristics?