To answer this question we will use the following expression to compute the probability that an event occurs:
[tex]\frac{FavorableOutcomes}{TotalOutcomes}.[/tex]Therefore:
[tex]\begin{gathered} P(Practitioner)=\frac{7}{19}, \\ P(Under45)=\frac{8}{19}, \\ P(Practitioner\text{ and }Under45)=\frac{2}{19}. \end{gathered}[/tex]Now, recall that:
[tex]P(A\text{ or }B)=P(A)+P(B)-P(A\text{ and }B).[/tex]Therefore:
[tex]\begin{gathered} P(Practitioner\text{ or }Under45)=P(Practitioner)+P(Under45)- \\ P(Practitioner\text{ and }Under45). \end{gathered}[/tex]Substituting
[tex]\begin{gathered} P(Practitioner)=\frac{7}{19}, \\ P(Under45)=\frac{8}{19}, \\ P(Practitioner\text{ and }Under45)=\frac{2}{19}, \end{gathered}[/tex]in the above equation we get:
[tex]P(Practitioner\text{ or }Under45)=\frac{7}{19}+\frac{8}{19}-\frac{2}{19}.[/tex]Simplifying the above result we get:
[tex]P(Practitioner\text{ or Under}45)=\frac{13}{19}.[/tex]Answer:
[tex]\frac{13}{19}.[/tex]