区间估计（一个参数&两个参数的区间估计）

一个参数的估计

估计均值

def mean_interval(mean=None,std=None,n=None,confidence=0.95):
    """
    """
    alpha=1-confidence
    z_score=ss.norm.isf(alpha/2)
    me=z_score*std/np.sqrt(n)
    low_limit=mean-me
    up_limit=mean+me
    return(round(low_limit,3),round(up_limit,3))

mean_interval(mean=105.36,std=10,n=25)

#(101.44, 109.28)

估计比例

def proportion_interval(p=None,n=None,confidence=0.95):
    alpha=1-confidence
    z_score=ss.norm.isf(alpha/2)
    me=z_score*np.sqrt(p*(1-p)/n)
    low_limit=p-me
    up_limit=p+me
    return(round(low_limit,4),round(up_limit,4))

proportion_interval(0.65,100)
#(0.5565, 0.7435)

估计方差

def var_interval(var=None,n=None,confidence=0.95):
    alpha=1-confidence
    chi_score0=ss.chi2.isf(alpha/2,df=(n-1))
    chi_score1=ss.chi2.isf(1-alpha/2,df=(n-1))
    low_limit=(n-1)*var/chi_score0
    up_limit=(n-1)*var/chi_score1
    return(round(low_limit,4),round(up_limit,4))

var_interval(93.21,25)
#(56.8295, 180.3897)