It's being derived from these other sample statistics.

它是从这些其他样本统计数据中得出的。

There's a 95% chance that 1.91, which is the sample statistic, or the statistic that we got, is within 1.96 times the standard deviation of this distribution of the true mean of of the distribution.

样本统计量或我们得到的统计量 1.91 有 95% 的几率在该分布的真实均值分布的标准差的 1. 96 倍以内。