3. A graduate's job prospect can be represented by a binary random variable X which takes the value 1 if a graduate has secured a job within the first six months after graduation and zero otherwise. (a) If the probability of a randomly selected graduate secured a job within the first six months after graduation is 0.6, find the expected value and the variance of X. [3 marks] (b) Assuming that samples of 2 fresh graduates are taken from the population, write down the probability function of the sample mean. [3 marks] (c) Find the expected value and the variance of the sample mean. What do you observe