如何計算投資的報酬/風險比例

https://blog.xuite.net/sandpiper/FX/31336442-%E5%A6%82%E4%BD%95%E8%A8%88%E7%AE%97%E6%8A%95%E8%B3%87%E7%9A%84%E5%A0%B1%E9%85%AC%2F%E9%A2%A8%E9%9A%AA%E6%AF%94%E4%BE%8B