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Prices of five distinct items in a sale reported by Jack were
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15 Sep 2026, 10:25
15 Sep 2026, 10:25
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Question Stats:
33% (00:45) correct
66% (01:11) wrong based on 3 sessions
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Prices of five distinct items in a sale reported by Jack were $ 257, $ 450, $ 550, $ 850 , and $ 1,020 . Exactly two of the prices were reported incorrectly: one was reported as $120 higher than its actual price, and the other was reported as $120 lower than its actual price.
Quantity A is greater.
Quantity B is greater.
The two quantities are equal.
The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
Standard deviation of the reported prices |
Standard deviation of the actual prices |
Quantity A is greater.
Quantity B is greater.
The two quantities are equal.
The relationship cannot be determined from the information given.
- Part of the project: GRE Daily Quant Challenge ALL 4 CORE QUANT AREAS
- Also replying to the unanswered questions
Re: Prices of five distinct items in a sale reported by Jack were
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01 Oct 2026, 05:15
01 Oct 2026, 05:15
Expert Reply
The relationship cannot be determined.
The mean of the reported prices is:
\(\frac{257+450+550+850+1020}{5}=625.4\)
The actual prices are obtained by subtracting 120 from one reported price and adding 120 to another reported price, so the mean stays the same.
Case 1:
Suppose 1020 was reported $ 120 too high, and 257 was reported $ 120 too low.
Actual prices:
\(900,450,550,850,377\)
The reported set has more extreme values, so the reported standard deviation is larger.
Case 2:
Suppose 257 was reported $\$ 120$ too high, and 1020 was reported $ 120 too low.
Actual prices:
\(
137,450,550,850,1140\)
Now the actual set has more extreme values, so the actual standard deviation is larger.
Since both cases satisfy the conditions but give opposite comparisons, the relationship cannot be determined.
The mean of the reported prices is:
\(\frac{257+450+550+850+1020}{5}=625.4\)
The actual prices are obtained by subtracting 120 from one reported price and adding 120 to another reported price, so the mean stays the same.
Case 1:
Suppose 1020 was reported $ 120 too high, and 257 was reported $ 120 too low.
Actual prices:
\(900,450,550,850,377\)
The reported set has more extreme values, so the reported standard deviation is larger.
Case 2:
Suppose 257 was reported $\$ 120$ too high, and 1020 was reported $ 120 too low.
Actual prices:
\(
137,450,550,850,1140\)
Now the actual set has more extreme values, so the actual standard deviation is larger.
Since both cases satisfy the conditions but give opposite comparisons, the relationship cannot be determined.
gmatclubot
Re: Prices of five distinct items in a sale reported by Jack were [#permalink]
01 Oct 2026, 05:15
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