분위와 분위수

표준정규분포에서의 4분위와 분위수

분위수 표준정규분포 4분위
$\text{1/4분위}$ $\text{2/4분위}$ $\text{3/4분위}$ $\text{4/4분위}$
4분위수

$\text{1/4분위수} \approx -0.67449$

$\text{2/4분위수} \approx 0$

$\text{3/4분위수} \approx 0.67449$

$\text{4/4분위수} =  \infty $

100분위수 $\text{25/100분위수} \approx -0.67449$ $\text{50/100분위수} \approx 0$ $\text{75/100분위수} \approx 0.67449$ $\text{100/100분위수} = \infty$

정규분포에서의 4분위와 분위수

분위수 정규분포 4분위
$\text{1/4분위}$ $\text{2/4분위}$ $\text{3/4분위}$ $\text{4/4분위}$
4분위수

$\text{1/4분위수} =\mu −2 \text{erfc}^{−1}(\frac{1}{2})\sigma$

$\text{2/4분위수} = \mu$

$\text{75/100분위수} =\mu +2 \text{erfc}^{−1}(\frac{1}{2})\sigma$

$\text{4/4분위수} = \infty $

100분위수 $\text{25/100분위수} =\mu −2 \text{erfc}^{−1}(\frac{1}{2})\sigma$ $\text{50/100분위수} = \mu$ $\text{75/100분위수} =\mu +2 \text{erfc}^{−1}(\frac{1}{2})\sigma$ $\text{100/100분위수} = \infty$