Suppose you identify a new element, Interactium. Interactium has three isotopes: Interactium-283, Interactium-286, and Interactium-292. In the mixture, 22% of the mixture is Interactium-283, 35% is Interactium-286, and the rest of the mixture is Interactium-292.

What is the relative atomic mass for Interactium?