1. We are given two actions with their payoffs for two states and we want to find the expected value for action A1. 2. The payoffs for action A1 are 100 for state 1 and 50 for state 2. 3. The states are equally likely, so the probability of each state is $\frac{1}{2}$. 4. The expected value (EV) formula for A1 is: $$\text{EV}(A1) = P(\text{state 1}) \times \text{payoff in state 1} + P(\text{state 2}) \times \text{payoff in state 2}$$ 5. Substituting the values, we get: $$\text{EV}(A1) = \frac{1}{2} \times 100 + \frac{1}{2} \times 50$$ 6. Simplifying: $$\text{EV}(A1) = 50 + 25 = 75$$ 7. Therefore, the expected value for action A1 is 75.