A. A discrete probability distribution of a random variable W is defined as follows: ( = ) = ^ , = , . , . , , . Determine the value of A. Give your answer to 3 decimal places. B. A discrete random variable T has the following piece-wise function: ( = ) = { ( ) = , , . = , Is this a valid probability distribution? Justify your answer. Construct a table similar to the one below to show your calculations.