Using the given information, we have the points (5.5, 60) and (8, 150). Let's find the ratio-
[tex]r=\frac{y_2-y_1}{x_2-x_1}[/tex]Where
[tex]\begin{gathered} x_1=5.5 \\ x_2=8 \\ y_1=60 \\ y_2=150 \end{gathered}[/tex][tex]\begin{gathered} r=\frac{150-60}{8-5.5}=\frac{90}{2.5} \\ r=36 \end{gathered}[/tex]This ratio represents the slope of the linear equation.
Then, we use the point-slope formula to find the equation that models this situation
[tex]\begin{gathered} y-y_1=m(x-x_1) \\ y-60=36(x-5.5) \\ y=36x-198+60 \\ y=36x-138 \end{gathered}[/tex]Now, we can find the number of pulls after 30 minutes using the equation
[tex]y=36\cdot30-138=942[/tex]