Question

A local politician claims that 1 in 5 automobile accidents involve a teenage driver. He is advocating increasing the age at which teenagers can drive alone. Over a 2 month period, there are 67 accidents in your city, and only 9 of them involve a teenage driver. If the politician is correct, what is the chance that you would have observed 9 or less accidents involving teenagers?


I have the correct answer, it's 0.0524, but I don't understand how to get this answer. Please help. (I would like to know how to do this by hand and also using a TI-84 calculator)

Thanks in advance.