Estimate
Estimation, Assumption
noun, verbal noun, の adjective
I will determine what you are inferring via an estimate.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
そのサバンの男は群衆の規模を534人と推定したのだが、実際の数とピッタリ当っていた。
The guy, who is a savant, estimated the scope of the crowd to have 534 people and he was exactly right.