The revenue that Yenni made is: $450 + $550 + $550 = $1550, that is, she sells a total of $1550 of electronics.
The commission is the 8% of $1550, which is computed as follows:
[tex]\begin{gathered} \frac{1550\text{ \$}}{x\text{ \$}}=\frac{100\text{ \%}}{8\text{ \%}} \\ 1550\cdot8=100\cdot x \\ \frac{12400}{100}=x \\ 124\text{ \$ = x} \end{gathered}[/tex]Therefore, she makes $124 in commission