Please state what exactly the answer is in the format given and how you get it, thanks.

Problem 12-05 (Algorithmic) The price of a share of a particular stock listed on the New York Stock Exchange is currently $39. The following probability distribution shows how the price per share is expected to change over a three-month period: Stock Price Change ($) Probability -2 0.30 0.05 0.10 0.05 0.30 0.15 0.05 2 4