Answer:
The treatment decays by half each week.
Explanation:
The decay function is given by:
![y=a(1-r)^(t)](https://img.qammunity.org/2021/formulas/mathematics/high-school/ppnx33xhts51iuvbezjs1arubgxvq3midi.png)
Here,
y = final value
a = initial value
r = decay rate
t = time
The decay function for one medications to treat dogs for fleas is:
![F(x)=4\cdot ((1)/(2))^(w)](https://img.qammunity.org/2021/formulas/mathematics/high-school/qe3j15zu46ruyti7s417e6d4f0dwf0pqd1.png)
Here the decay rate is:
![1-r=(1)/(2)\\\\r=1-(1)/(2)\\\\r=(1)/(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/hgi9qq0grv3ltws1u9xpu2mpxafi2tzxy7.png)
The treatment decays by half each week.