[填空题]
The following table shows the number of rw.7pst9b a ,qovertime sd25n63cnjv3 zmjgb0au 5xz) hours worked by employees in a compan6j x suzncz)b33a2m 55j0nvdgy.
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. ≈