送交者: wasguru 于 2009-05-30, 18:34:34:

回答: 是么？=0, =0 由 wasqaz 于 2009-05-30, 18:25:56:

• 方差相等也是两个随机变量之间的关系 - wasguru (114 bytes) 2009-05-30, 18:53:11 (331359)
• and have equal variances - wasqaz (25 bytes) 2009-05-30, 18:49:01 (331356)

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