You can use either a Z table or technology like Microsoft Excel to convert the given probability/area over into a Z score value!
When I do that I find that the corresponding value in the table that goes with probability = (0.50 + 0.4599) = 0.9599 is Z = 1.75.
Meaning that the Z score that lies to the right of the mean and has an area of 0.4599 between it and the mean is 1.75.