Translation of "accidental" into Chinese

The real test came one day when he accidentally knocked over the glass of a customer in a bar.

不久真正的考验临到了。 一天,布埃纳文图拉在酒吧里无意中打翻了一个男子的酒杯。

Expressed through standard deviation: Values given over accidental errors

通过标准偏差来表示: 其数值与随机误差关系较大 。