The atomic mass of titanium is 47.88 u.
The average atomic mass of Ti is the weighted average of the atomic masses of its isotopes.
We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its % abundance).
Thus,
0.0800 × 45.953 u = 3.676 u
0.0730 × 46.952 u = 3.427 u
0.7380 × 47.948 u = 35.386 u
0.0550 × 48.948 u = 2.692 u
0.0540 × 49.945 u = 2.697 u
_________TOTAL = 47.88 u