Please pay attention to the Pinyin Final (韵母) - 'i' this Chinese character '比' carries, which connect it with the other example symbols.
pinyin: bǐ; means comparison, to compare.

Chinese phrase: 比较 bǐ jiào - to compare

Examples:

毕 pinyin: bì; means to finish, accomplish.
Chinese phrase: 毕业 bì yè - to graduate, graduation


屁 pinyin: pì; means wind from bowels
Chinese phrase: 放屁 fàng pì - break wind


批 pinyin: pī
Chinese phrase: 批评 pī píng - to criticize, refute