Translation of "extent" into Japanese

To what extent can you answer for his deed?

彼の行動にどの程度まで責任が持てますか。

Hence, he should have freedom only to the extent that it does not unjustly interfere with that of others.

そのため,人の持つ自由は他の人の自由を不当に侵害しない範囲に限られるべきです。

Let all of us be industrious and useful to the full extent of our strength and ability.

勤勉に働き,役に立つ者となるために,力と能力の限りを尽くそうではありませんか。