[填空题]
A population of endan j)2-ryfj;n uagered s;0hxtc71 lqoae-e 7rrnow leopards, P , can be modelled by the equation
$P_{t}=P_{0} e^{k t}$
where $P_{0}$ is the initial population, and t is measured in years.
1. After one year, it is estimated that $\frac{P_{1}}{P_{0}}=0.93 $.
1. Find the value of k .
2. Interpret the meaning of the value of k .≈
2. Find the least number of whole years for which $\frac{P_{t}}{P_{0}}<0.50$ . t =