Set S consists of integers {8, 11, 12, 14, 15}

Set S consists of integers {8, 11, 12, 14, 15}. If integer n is included in the set, the average (arithmetic mean) of set S will increase by 25%. What is the value of integer n?

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 #45288