Solution

 

d. We observe that

For $P(A) \ge 0.5$, as $P(A)$ increases, $E(x)$ decreases.

Answer

a. 4.0656   b. 4.125    c. 3.3186

d. For $P(A) \ge 0.5$, as $P(A)$ increases, $E(x)$ decreases.