<P> Consider the simple experiment where a fair coin is tossed four times . Find the probability that exactly two of the tosses result in heads . </P> <P> For this experiment, let a heads be defined as a success and a tails as a failure . Because the coin is assumed to be fair, the probability of success is p = 1 2 (\ displaystyle p = (\ tfrac (1) (2))). Thus the probability of failure, q (\ displaystyle q), is given by </P> <Dl> <Dd> q = 1 − p = 1 − 1 2 = 1 2 (\ displaystyle q = 1 - p = 1 - (\ tfrac (1) (2)) = (\ tfrac (1) (2))). </Dd> </Dl> <Dd> q = 1 − p = 1 − 1 2 = 1 2 (\ displaystyle q = 1 - p = 1 - (\ tfrac (1) (2)) = (\ tfrac (1) (2))). </Dd>

Which of the following is not an example of a bernoulli random variable