A quantity $P$ is an exponential function of time $t .$ Use the given information about the function $P=P_{b} a^{t}$ to:
(a) Find values for the parameters $a$ and $P_{0}$.
(b) State the initial quantity and the percent rate of growth or decay.
$P_{0} a^{3}=75 \quad$ and $\quad P_{0} a^{2}=50$