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falseNote 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.5.2.2.5: 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.5.2.2.7: 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. 5.2.2.8: 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.TIF G: Customer satisfaction depends on many factors, not just average speed. Grocery stores have /categories/ of checkout lines: express lanes, automated self-checkout lanes, and so on. Also, it turns out that the ability to switch lanes if someone in front of you turns out to be really slow gives customers some feeling of control over their wait time (whether or not it's really effective). And the fact that each customer is wheeling a long cart in front of them would make a single line /look/ very long, even if the number of customers isn't so large. At the bank, it's hard to predict which customers will turn out to have time-consuming problems. (But the bank does have the equivalent of self-checkout lanes, ATMs, just not right next to the human tellers. And they do have a few special lines, for business customers, opening an account, etc.)infected?truesick

start timeclones ready?trueelapsed time1000vanish

false

10010052true