Measures of spread

Anna, Ben and Charlie have been estimating 30 seconds. Who is the best?

Can you find sets of numbers which satisfy each of our mean, median, mode and range conditions?

Invent a scoring system for a 'guess the weight' competition.

Your data is a set of positive numbers. What is the maximum value that the standard deviation can take?

Does weight confer an advantage to shot putters?

Given the mean and standard deviation of a set of marks, what is the greatest number of candidates who could have scored 100%?