If the coin were fair, then the standard deviation for flips is 12√≈16, so a result with heads is roughly 6 standard deviations from the mean. Instant online coin toss. Heads or tails? Just flip a coin online! Standard error in the case of flips is /sqrt()=18 and in in the case with 10 flips it is is more than 3 standard deviations away from the null hypothesis of a fair coin (p( heads)>).