Answer
Element "X" is Titanium (Ti).
Work Step by Step
Average atomic mass = $0.0800*45.95232+0.0730*46.951764+0.7380*47.947947+0.0550*48.947841+0.0540*49.944792=47.9$ amu
Referring to the Periodic Table, we see that Titanium has an average atomic mass of 47.867 amu which most closely matches Element X's average atomic mass of 47.9 amu. Therefore Element "X" is most likely Titanium.