The tree diagram below shows a potential coronavirus chain of transmission. Each dot represents an infected person. One infected person (the person at the top of the diagram) spreads the coronavirus to others, who then spread it to others and so on.
The tree diagram can help us model the number of new infections over time. Specifically, let’s define each horizontal layer of dots as representing the number of new infections on a certain day. The top layer, representing Day 0, depicts just one newly infected person (one dot). The next layer down, representing Day 1, depicts two newly infected people (two dots). The following layer, representing Day 2, depicts four newly infected people (four dots).
3a.) Create an exponential model based on the coronavirus transmission data on the pre-vious page.
3b.) Based on your model, approximately how long will it take before 500 people are infected by Covid?
3c.) Look up how many total Covid infections there have been since the start of the pan- demic. Does your model agree with the data? If not, how could you modify your model to fit the data better?