The expected value is given by:
[tex]E(Y)=\sum ^n_{i\mathop=0}y_iP(y_i)[/tex]Therefore:
[tex]\begin{gathered} E(Y)=(-2\cdot0.02)+(-1\cdot0.06)+(0\cdot0.19)+(1\cdot0.14)+\ldots+ \\ +\cdots+(2\cdot0.53)+(3\cdot0.04)+(4\cdot0.02) \\ E(Y)=1.3 \end{gathered}[/tex]