# How to calculate the randomness of a sample and if it is representative on r?

I am doing a project on R commander and the project says, "The set of exoplanets discovered to this day is a sample of all exoplanets that exist in the universe. Discuss whether you think this sample is random (i.e., representative of the population)." How do I calculate this on R commander?

• I believe you're being asked to think rather than calculate. – Scortchi - Reinstate Monica May 13 '15 at 13:36
• ok but how can I prove it? That's what I'm not sure of.. – alexander sarandiev May 13 '15 at 13:58
• Asking if the sample's random is short for "was it obtained by (simple) random sampling?". Unless you have either data on undiscovered exoplanets or theoretical predictions to compare to your sample, you need to think about the methods used to detect exoplanets. – Scortchi - Reinstate Monica May 13 '15 at 15:10
• I only have data on exoplanets discovered. So that means I draw a conclusion based on the quantity of exoplanets discovered? – alexander sarandiev May 13 '15 at 16:05
• I think you can assume it's a small proportion of the number of exoplanets out there. But can you assume "each individual has the same probability of being chosen at any stage during the sampling process"? (Did you look at the Wikipedia articles I gave links to?) – Scortchi - Reinstate Monica May 13 '15 at 16:12