Two assumptions underpin the scenario, published in the journal Lancet Infectious Diseases.
One is that every person with Ebola will go on to infect 2.49 other people, statistically speaking.
The other is based on the state of health measures that prevailed in Montserrado as of September 23.
Thus the total of 170,996 cases by December 15 is based on the assumption that the September 23 level of response goes unchanged.
If, during November, another 4,800 beds are installed at treatment centres and health workers speed up fivefold the detection rate of Ebola cases, 77,312 Ebola cases could be averted by December 15, the study said.