正态总体方差已知时，在小样本条件下，总体均值在 [tex=1.929x1.143]yh3n57YpM0RFxvBYRVe30A==[/tex] 置信水平下的置信区间可以写为[input=type:blank,size:4][/input]。 未知类型：{'options': ['[tex=5.357x2.786]rgT+dRllwmLDhFQldNsgE/Ik8vjGgQN3JCmaVFOAggXQJS4ll8t7yYDqeMFnFXajnOSzE9PdhekpGChVwk5d2g==[/tex]', '[tex=5.214x2.429]nc6fcPS4chy6v2YUOLIF7EGdbxzZBYaFFcfjN2n4PYpS5SLN/Ioph/bUQWytjGJE[/tex]', '[tex=5.357x2.429]rgT+dRllwmLDhFQldNsgE/Ik8vjGgQN3JCmaVFOAggVnUnDrwMgz6FH5iPKcW+ldUGpYAp0mGlVRfN9mQxtjcw==[/tex]', '[tex=4.714x2.5]rgT+dRllwmLDhFQldNsgE/Ik8vjGgQN3JCmaVFOAggVP0FqJQ4qRHev6lUgN9e7+[/tex]'], 'type': 102}