コスト効率[kosutokouritsu] cost effectiveness
圧縮率[asshukuritsu] compressibility
引率[insotsu] leading
円周率[enshuuritsu] Pi (3.1415926..)
黄金率[ougonritsu] golden mean

拡大率[kakudairitsu] rate of magnification
確率[kakuritsu] probability
確率モデル[kakuritsumoderu] stochastic model
確率過程[kakuritsukatei] stochastic process
確率誤差[kakuritsugosa] random error