An introductory video to the Probability and Evidence collection
99% of people who have measles have spots. Ben has spots. Do you think he has measles?
I'd be very surprised if I had three children all with the same birthday, but I read in the paper that it happened to one family...
In 1% of cases, an HIV test gives a positive result for someone who is HIV negative. How likely is it that someone who tests positive has HIV?
DNA profiling is an invaluable tool for the police. However, when it comes to probability, things aren't always as straightforward as they seem.