[填空题]
The following table shows the number lu yw)j*r3+ .cgnl7/in bjv; apt 9s7fof overtime ha8 c.luwd;r /23uhlj rours worked by employees in a companyr8a u r/3w llh;.dc2uj.
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. ≈
