For this, you need to know 1) the mass of the hydrate and 2) the mass of the anhydrous salt. Once you have both of these, you will subtract 1) from 2) to find the mass of the water lost.
From the problem, you know that 1) = 2.000 g.
Now you need to find 2). You know that your crucible+anhydrous salt is 5.022 g. To find just the anhydrous salt, subtract the mass of the crucible (3.715 g).
1) = 5.022 g - 3.715 g = 1.307 g
Now you can complete our original task.
Mass H2O = 2) - 1) = 2.000 g - 1.307 g = 0.693 g.
