Each Course at a Large University Has Either a Final

Essay

Each course at a large university has either a final exam or a final paper. The table
below presents the distribution of the number of final exams that students at the
university take in the Fall term, and their associated probabilities. What is the mean
of this distribution? $$\begin{array} { | l | c | c | c | c | } \hline \boldsymbol { x } & \mathbf { 0 } & 1 & 2 & 3 \\\hline \boldsymbol { P } ( \boldsymbol { x } ) & \mathbf { 0 . 0 5 } & \mathbf { 0 . 2 5 } & \mathbf { 0 . 4 0 } & \mathbf { 0 . 3 0 } \\\hline\end{array}$$