problem Snow and Cholera Age 14 to 16 Challenge level What information helped medical pioneers decide on the cause of a disease? Especially in a time before microscopes were as powerful as they are today ?
problem Counting Fish Age 14 to 16 Challenge level I need a figure for the fish population in a lake. How does it help to catch and mark 40 fish?
problem Very old man Age 16 to 18 Challenge level Is the age of this very old man statistically believable?
problem Robin's hypothesis testing Age 16 to 18 Challenge level How many trials should we do in order to accept or reject our null hypothesis?