population growth models can be used to describe actual occurrences in a population. For example, during a pandemic, we can see the mortality ratio of disease by looking at the population's decrease in the number of individuals.
Also, if the population growth model covers a longer timeline, we can deduce some events that occurred in the past. Taking the same example of the pandemic, we would see a decrease in population numbers at the time the pandemic was present.
Finally, if the collected data for the population growth models is enough we can use it to predict future changes in the population's numbers, this by statistical methods
Therefore, the answers would be 1, 2 and 4