If we want to change a standard error from 12 to 4 by changing the sample size, we need to multiply the original sample size by
A) 3 .
B) 9 .
C) $\frac{1}{3}$.
D) $\frac{1}{9}$.

Question

Quizplus · Accepted Answer

The standard error of the mean is inversely proportional to the square root of the sample size (n). To reduce the standard error from 12 to 4, which is a factor of 3, we need to increase the sample size by a factor of 3^2 = 9, because the relationship is squared.

If We Want to Change a Standard Error from 12 13\frac{1}{3}31​

If We Want to Change a Standard Error from 12 $\frac{1}{3}$