Answer
See below.
Work Step by Step
By definition, the expected value is the sum of each outcome multiplied by its probability.
Hence here the expected value: $\frac{3}{4}\cdot(5-4)+\frac{1}{4}\cdot(-4)=-\frac{1}{4}$.
This means that in the long run a player is expected to lose $\frac{1}{4}$ each turn he plays on average.
