[填空题]
A population of endangered snow.vmpyl 2v)g m.f, xl1rtuf s:3 leopard, nivbm h;m;7voq2fu 9s, 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 $\frac{P_{t}}{P_{0}}<0.50$ .
