Suppose X is a discrete random variable with a probability mass function px (x) - c(4 -

Question:

Suppose X is a discrete random variable with a probability mass function px (x) - c(4 - x) for x in { - 1,2,3}, and Px (x) = 0 otherwise.
a. What is the value of c so that px (x) is a mass?
b. Make a plot of the probability mass function.
c. What is the CDF of X?
d. Make a plot of the CDF.