To find XZ, we should use the Segment Addition Postulate. This postulate tells us that, if we have a point between two points, we can add the lengths of the two smaller segments to find the longer segment length. In our case, Y is between X and Z, so we can get the length of XZ by adding XY and YZ.
XZ = XY + YZ
From the diagram, we know that the length of XY is 17 and the length of YZ is 24. Now, we can use this to calculate XZ.