Final answer:
The question seems to refer to a logistic growth function for estimating population, but without additional context or parameters specific to the global population, it is not possible to provide an accurate estimation for the population in 2020.
Step-by-step explanation:
The student's question does not provide a clear context or formula that directly correlates to the estimated global population in the year 2020. However, to estimate a population size at a given time using a mathematical growth model, one typically uses an exponential or logistic growth function. Exponential growth can be calculated using the formula P(t) = P0e(r*t), where P(t) is the population at time t, P0 is the initial population, e is the base of the natural logarithm, and r is the rate of growth. Logistic growth is more complex and accounts for a carrying capacity, and might take the form of P(t) = K / (1 + ( (K - P0) / P0) * e^(-r*t)), where K represents the carrying capacity. The example provided seems to be of a logistic model where the population is calculated using an initial population and growth rate impacted by another exponential factor. Without specific parameters for the function relating to the actual global population, we cannot accurately estimate the population for a future year.