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the technique of mapping over the numbers from 1 to 10, without actually using the selected number, to call the simulator ten times. It'll make us very happy if your students can write this HOF-based solution readily by this point in the course, although it's also fine if they remember that they have an AVERAGE block in their math block library.5.2.2.6: Students will get different numbers depending on the speed of their computers. We get 10.76, 4.78, 2.94, and 1.60 seconds. The effect of population density on the rate of infection turns out to be more important than the fact that more people means more infections needed to include everyone. It's tempting to say that time ≈ 450/size, but if you multiply it out, the speedup for larger populations is a bit greater than that formula would imply.
5.2.2.7: The best way to investigate such questions is to reprogram the simulation and see how varying various parameters affects the result. If only some encounters lead to infection, does everyone still eventually get sick? What if people recover after five cycles? What if some fraction of the population is naturally immune? And so on.5.2.2.4: The most obviously unrealistic assumption is that an infected person remains infected forever, neither dying nor getting well. This makes our simulation useless in a real situation; one of the big unanswered questions as we write this is the death rate among people who get infected. Most likely there are many people who get infected but have no symptoms or easily managed (mild) symptoms and so don't show up at the hospital for treatment. As a result, we know only the rate at which people with serious symptoms die. Another very important simplifying assumption is that everyone who comes in contact with an infected person is infected. In reality, not only is there a less-than-100% rate, but the rate differs in different populations; old people, for example, are more at risk. More answers are possible.infected?truesickstart timerunningtrueelapsed time1000vanishfalse5true161589951008319.13410052