The average of five results is 45 and that of the first…

The average of five results is 45 and that of the first four is 45. The fifth result is?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #74507