The energy of a system as a function of time $t$ is given as $E\left(t\right)=A^2\exp \left(-\alpha t\right)$ , where $\alpha =0.2s^{-1}$ . The measurement of A has an error of 1.25%. If the error in the measurement of time is 1.50%, the percentage error in the value of $E\left(t\right)$ at $t=5s$  is