表示单次测量结果在某一区间的概率通常为 :P{|x -μ|≤ Kσ}PT ( 1 )　　如单次测量值的误差小于等于 1 σ的概率为68% ;单次测量值的误差小于等于 2 σ的概率为95% ;单次测量值的误差小于等于 3σ的概率为99.7%。在一般情况下 ,对某量进行 n次测定 ,得到平均值 x和标准偏差 , P (| x -μ | ≤ Kσ) PT (1) If a single measurement error is less than or equal to 1 σ probability of 68%; a single measurement of the probability of The probability that the error is less than or equal to 2 σ is 95%. The probability that the error of a single measurement is less than or equal to 3σ is 99.7%. Under normal circumstances, the determination of an amount of n times to get the average x and standard deviation,