2382数学简单数值题short

Remaining Variance Fraction Under Pairing 12

题目

Without common random numbers, two independent estimators have standard deviations 4 and 5, so the variance of their difference is 4^2+5^2. With pairing, the observed paired-difference standard deviation is 3. What fraction of the unpaired difference variance remains?

解题计时

0:00

提交作答时记录，用于后续平均用时统计。

你的答案

数值

支持题库 schema 允许的整数、小数、分数或四则表达式。