We have the following:
The first thing is to pass the mixed numbers to fractional numbers, like this
[tex]\begin{gathered} -1\frac{1}{4}=-\frac{4+1}{4}=-\frac{5}{4} \\ 2\frac{1}{2}=\frac{4+1}{2}=\frac{5}{2} \end{gathered}[/tex]now, to know the change, we must multiply the exchange rate by the time elapsed thus
[tex]-\frac{5}{4}\cdot\frac{5}{2}=-\frac{25}{8}=-3\frac{1}{8}[/tex]The total change is -3 1/8 or -25/8