Official Guide Explanation:
Data Sufficiency #D31




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Solution and Metadata

Question: D31
Page: 24
Difficulty: 6 (Moderately Difficult)
Category 1: Arithmetic > Descriptive Statistics > Standard Deviation

Explanation: Statement (1) is sufficient. You will rarely see the term "variance" on the GMAT; when you do, recognize that it is the square of the standard deviation. It's that simple--if the variance for the set is 4, the standard deviation is rt[4] = 2.

Statement (2) is also sufficient. It is a long - winded definition of standard deviation. SD measures the average difference between the mean and each term in the set. If every term in the set is 2 away from the mean, the average distance is 2, meaning that the SD is 2. Choice (D) is correct.

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