need help on my study guide please

A set of eight places identified as: {a,b,c,d,d,e,f,g,h} depicts sites of varying traffic congestion: and, the statistical state of traffic indicated below refers to a random variable (x) denoting an index of over-congestion. Corresponding probabilities p(x) of occurrence of x are also listed: Determine the following with reference to the RV: (i) Find the expected average performance of the RV (x), (ii) Find the variance of x (iii) Based on central tendency considerations, decide the most probable site of the heavy traffic congestion (iv) Cumulative probability of the RV up to the median value: PX(x