What is the average atomic mass of titanium on that planet

average atomic mass = 46.8509984 amu

Explanation:
To get the average atomic mass, we will follow these steps:
1- multiply the atomic mass of each isotope by its percentage of abundance
2- add the products

We are given that:
1- The first isotope has an atomic mass of 45.95293 and percentage of abundance equals 72%
2- The second isotope has an atomic mass of 47.94795 and percentage of abundance equals 11%
3- The third isotope has an atomic mass of 49.94479 and percentage of abundance equals 17%

Following the mentioned steps, we can get the average atomic mass as follows:
average atomic mass = (45.95293)(0.72)+(47.94795)(0.11)+(49.94479)(0.17)
                                   = 46.8509984 amu

Hope this helps :)