Question

1. Assume that 55% of Americans wear a face mask when leaving home.  

a. When you leave the house, how many people should you expect to see before seeing someone wearing a face mask?

​​​​​​ b. What is the probability that no one is wearing a face mask until the fifth person you see?

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c. On your trip to the grocery store, you encounter 50 people. What is the probability that at least half of them are wearing face masks?

​​​​​​ d. What is the probability that exactly half of the 50 people you encounter are wearing face masks?

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e. Some say that seeing others wearing face masks encourages people to wear face masks. Does this make you question any assumptions you made while calculating probabilities above? Explain.

2. 55% of respondents who left the house the previous week reported using face masks or face coverings when leaving home.

​​​​​​a. Are conditions satisfied to calculate a confidence interval? Justify your answer.

b.​​​​​Calculate a 99% confidence interval.


​​​​​ c. State what your interval means in the context of the problem.

​​​​​d. Can we say definitively that the majority of Americans are wearing face coverings when leaving the house? Explain.

Answer 1