You can get "1 in 10000" significance without 10000 people. (How many Tails in a row would you need to flip a coin to believe it's not random at that level? S

You can get "1 in 10000" significance without 10000 people. (How many Tails in a row would you need to flip a coin to believe it's not random at that level? Somewhere between 13 and 20?) Also, many datasets (think financial data or census data) are much bigger.