### Very Old Man

Is the age of this very old man statistically believable?

# Reaction Timer Timer

##### Stage: 5 Challenge Level:

The reaction timer problem introduces this interactivity which measures the amount of time taken to react to a shape appearing on-screen:

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In this interactivity it is known that once a shape disappears an internal timer begins. The time until the appearance of the next shape is determined randomly through a clear, well-defined statistical process which is unknown to us. From the moment that this next shape disappears the timer resets and starts again; the random process then again determines the time until the appearence of the next shape. Familiarise yourself with the interactivity before considering this question:
• Upon each shape disappearing there is a delay of a random length until the appearence of the next shape. How might you design an experiment to determine the nature of the random process giving rise to the delay?
Once you have designed the experiment, perform it and analyse the data. Can you produce a clear hypothesis as to the random process giving rise to the delay?