In order to calculate the rate r (in this case, the speed), we can use the following formula:
[tex]\begin{gathered} \text{distance}=\text{speed}\cdot\text{time} \\ d=r\cdot t \end{gathered}[/tex]So, using the values of d = 2730 and t = 9.75, we have:
[tex]\begin{gathered} 2730=r\cdot9.75 \\ r=\frac{2730}{9.75} \\ r=280 \end{gathered}[/tex]So the value of r is equal to 280 miles per hour.