Final answer:
The statistics that helped lead to the discovery of EI in biology are the observation of the bacteria's growth rate and the test result showing the presence of specific enzymes involved in the EI pathway.
Step-by-step explanation:
The statistics that helped lead to the discovery of EI in biology are the observation of the bacteria's growth rate, as well as the test result showing the presence of specific enzymes involved in the EI pathway. The growth rate observation indicates that the bacteria can efficiently use the EI pathway to produce energy. The presence of the enzymes further confirms the utilization of this pathway by the EI bacterium.