We have a four sided die and the die is not fair meaning that the probability of getting "1" is 3 times (*3) the probability of getting other values (2,3,4) but the probability of the other possibilities are equal. We define the random variable Z which shows the number when we roll the die. Calculate the following(5 point each):

1. What is the expected value of Z?
2. What is the probability mass function for the random variable Z?
3. Is it Uniform distribution? Explain your answer.