This is the 4431st most frequent Japanese word.
基づい
Based on; grounded on.
The word "基づいて" here signifies "based on" or "taking as reference," indicating reliance on his opinion as the foundation for modifying the plan.
彼の意見に基づいて計画を変更しました。
The plan was modified based on his opinion.
"基づく" in this instance also implies reliance or action in accordance with a foundation, in this case, the legal framework.
法律に基づく行動が求められます。
Actions are required to be based on the law.
The term "基づいた" in this sentence is used as a past participle form, denoting that the analysis was performed with actual data as its basis or source.