[填空题]
The following table shows the nobtl xq+ u7tv 81:.qgjumber of -,dp.cgsz pzt.zue-:overtime hours worked by employees in a compzpd- c .z,teug: ps.-zany.
It is known that the mean number of overtime hours is 1 .
1. Find the value of x .
2. Find the standard deviation of the data. ≈
