Celebrities become politicians by utilizing the proportional representation of the electoral system.
Please be aware that your beauty is in direct proportion to the increase in the number of WaniKani users, Koichi.
Foreign language ability doesn’t always improve in proportion to the rate of change.
This is a tough one. When you compare examples (in this case of numbers) you are figuring out the proportion / ratio. A ratio, for example, has one number on top of another. They are examples being compared. Same with proportions. Without two things to compare, proportion doesn't make sense. That's why when you compare examples, you are dealing with proportions or ratios.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.