A fair coin is tossed 28 times. what is the probability that at most 25 tails occur?

Using the concept of binomial probability, the probability of obtaining at most 25 tails is 0.999Recall : P(x = x) = nCx * p^x * q^(n-x) p = probability of success = 0.5 n = number of trials = 28q = 1 - p = 0.5 The probability of tail occurring at most 25 times can be defined thus :P(X ≤ 25) = P(X = 0) + P(X = 1) +... + P(X = 25) Using a binomial probability calculator : P(X ≤ 25) = 0.999Therefore, the probability of obtaining at most 25 tails is 0.999Learn more :