sigma 与不合格率, Cpk关系

φ( - x ) = 1 –φ( x )

x正态分布累积概率 φ(x)Sigma -69.86588E-10±1 Sigma -5 2.86652E-07±2 Sigma -4.5 3.39767E-06±3 Sigma -4 3.16712E-05±4 Sigma -3.50.000232629±5 Sigma -30.001349898±6 Sigma -2.50.006209665

-20.022750132

-1.50.066807201

-10.158655254

-0.50.308537539

00.5

10.841344746

20.977249868

2.50.993790335

30.998650102

3.50.999767371

40.999968329

4.50.999996602

50.999999713

5.50.999999981

60.999999999

6.51

71

7.51