Answer: The answer is [tex]2\dfrac{4}{9}~\textup{times}.[/tex]
Step-by-step explanation: Given in the question that
Time taken by Harrison to finish his history project is given by
[tex]t_1=1\dfrac{1}{2}=\dfrac{3}{2}~\textup{hours}.[/tex]
and the time taken by Kiles to finish his science project is
[tex]t_2=3\dfrac{2}{3}=\dfrac{11}{3}~\textup{miles}.[/tex]
Let the time taken by Miles to finish his science project be 'p' times that of the time taken by Harrison to finish his history project.
Therefore,
[tex]t_2=p\times t_1\\\\\Rightarrow p=\dfrac{t_2}{t_1}=\dfrac{\frac{11}{3}}{\frac{3}{2}}=\dfrac{11}{3}\times \dfrac{2}{3}=\dfrac{22}{9}=2\dfrac{4}{9}.[/tex]
Thus, Miles take [tex]2\dfrac{4}{9}[/tex] times more time than Harrison.