$$\sqrt { \frac { \sigma _ { 1 } } { n _ { 1 } } + \frac { \sigma _ { 2 } } { n _ { 2 } } }$$ The standard error of difference of two large (independent) sample means is

Question

Quizplus · Accepted Answer

When the sample size is large for both samples, the standard error of the difference of means can be approximated by the square root of the sum of the variances divided by the sum of the sample sizes. Therefore, the given formula is correct.

σ1n1+σ2n2\sqrt { \frac { \sigma _ { 1 } } { n _ { 1 } } + \frac { \sigma _ { 2 } } { n _ { 2 } } }n1​σ1​​+n2​σ2​​​

$\sqrt { \frac { \sigma _ { 1 } } { n _ { 1 } } + \frac { \sigma _ { 2 } } { n _ { 2 } } }$