The average of 9 numbers is 104

The average of 9 numbers is 104. Average of the first 5 of them is 99 and that of the last 5 is 100. Find the 5th number?

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 #27065