[詞彙Q&A] Q: percent，percentage ，rate ，ratio ，proportion 有什麼區別?

A: percent (%)百分之(某數字) 一般都是有數字在前面的時候用 (數字＋percent of sb or sth)

E.g. I only answered 20 percent of the questions correctly. You shouldn't have copied my answers.

E.g. 85% of Eric’s paycheck goes to his wife. The other 15% goes to the government. Both do nothing for Eric.
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percentage百分率
通常在 the／a small／a large...＋percentage of sb or sth 的時候用

1. Percentage被放在 the後時，用單數形動詞：
E.g. The percentage of uneducated people in this city is relatively small. Nearly everyone has a bachelor's degree or above.

當被放在 a後時，可用動詞單數或複數形式，這由後面所跟的名詞數量而定：

E.g. A large percentage of children in the school come from single-parent families.

E.g. A large percentage of the crop has spoiled.
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rate指的是比率，比值，率等，如tax rate稅率,crime rate犯罪率等。

E.g. The crime rate in this city is rapidly increasing. There are violent crimes happening almost every day.
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ratio指的是兩個量的比值，其實是強調相比、相除的關係，但是它的兩個量必須在上下文出現。比例 (必須有確切的數字)

E.g. The ratio of students to teachers is 35:1.
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proportion是指比例關係，可代替ratio使用，但是在相比的兩個量在上下文沒有出現是必須用proportion而不能用ratio。

E.g. Only a tiny proportion of the population is infected by the H7N9 virus.