Weight should be proportional to height.

重量应该是比例与高度。

The output should be proportional to the input.

输出应当与输入成正比。

The output should be proportional to the input.

输出应当与输入成比例。

Payment will be proportional to the amount of work done.

酬金将与工作量成比例。

Still going to be proportional to the total system energy.

,仍然正比于,系统的总能量。