[填空题]
The following table shows the number of .v9n13f wrtpa overtime houtcx4dm,i9j27 g qyk.e fm1lz3 rs worked by employees in a compxtj4 9d3kligy 7 2fme1.m ,zcqany.
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. ≈