问道国外的数学题(t)n(T)=500*0.81 The function above can be used to m

问道国外的数学题
(t)
n(T)=500*0.81
The function above can be used to model the population of a certain endangered species of animal. If n(t) gives the number of the species living t decades after the year 1900, which of the following is true about the population of the species from 1900 to 1920 ?
详细写下做的过程
小t在0.81上 （t)
写错了是，n(T)=500*0.81
着是选者
1.It increased by about 1,000.
2.It increased by about 320.
3.It decreased by about 180.
4.It decreased by about 320.
5.It decreased by about 1,000.
最后答案是3