The population is increasing by a continuous exponential growth model. Then, it follows the next formula:
![P(t)=P_0e^(rt)](https://img.qammunity.org/2023/formulas/mathematics/college/lnfr7gitu9gkx8j6gxi5kxu0labi2nwv38.png)
Where P=2265, Po= ?, r=15% = 0.15 and t=5.
P = final population
P0= initial population
r= rate
t= time
Replacing with the given values:
![2265=P_0e^(0.15\ast5)](https://img.qammunity.org/2023/formulas/mathematics/college/phvum6mjskhsby3jfxibfkwijl7ypd7hf7.png)
Solve for Po:
![P_0=(2265)/(e^(0.15\ast5))](https://img.qammunity.org/2023/formulas/mathematics/college/2k4im150oidratz2v16kr1a7j2jd19r7w4.png)
Then
![P_0=1070](https://img.qammunity.org/2023/formulas/mathematics/college/6cunj1jtbaroowsdp2ih9iwst17hznit26.png)
Hence, the number of bacteria in the initial sample is 1070.
(The value is rounded to the nearest integer).