The mean (μ) of a probability distribution for a discrete variable is:
[tex]\mu=\Sigma y\cdot P(y)[/tex]
where P(y) are the probabilities of y-values.
Substituting with the values of the table:
[tex]\begin{gathered} \mu=-19\cdot0.23-18\cdot0.13-17\cdot0.1-16\cdot0.04-15\cdot0-14\cdot0.5 \\ \mu=-4.37-2.34-1.7-0.64-7 \\ \mu=-16.05 \end{gathered}[/tex]
