TeX source:

\mathrm{MQK}_{i}=\left(\mathrm{MC}_{i}^{\max }-\mathrm{MC}_{i}^{\min }\right) /\left(\mathrm{MQ}_{i}^{\max }-\mathrm{MQ}_{i}^{\min }\right) ; \quad \mathrm{MC}_{i}^{\min }=\operatorname{minimum} \quad