For example, say an experiment is performed to determine if a coin flip is fair (50% chance of landing heads or tails), or unfairly biased, either toward heads (> 50% chance of landing heads) or toward tails (< 50% chance of landing heads). Since we consider both biased alternatives, a two-tailed test is performed. The null hypothesis is that the coin is fair, and that any deviations from the 50% rate can be ascribed to chance alone. Suppose that the experimental results show the coin turning up heads 14 times out of 20 total flips. The p-value of this result would be the chance of a fair coin landing on heads at least 14 times out of 20 flips plus the chance of a fair coin landing on heads 6 or fewer times out of 20 flips. In this case the random variable T has a binomial distribution. (1) The probability that 20 flips of a fair coin would result in 14 or more heads is ____? (2) The probability that 20 flips of the coin would result in 14 or more heads or 6 or fewer heads is ______?

this was a level 1 question and I still dont remember… thats sad…

it’s not that straightforward to me

Don’t post this cr*p in the LII forum a fortnight before the exam