daria92
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A bacteria population increases exponentially at a rate of r% each day. After
32 days, the population has increased by 309%. Find the value of r.

Respuesta :

Answer:

r=4.5% daily

Step-by-step explanation:

Exponential Growth

The natural growth of some magnitudes can be modeled by the equation:

[tex]P=P_o(1+r)^t[/tex]

Where P is the actual amount of the magnitude, Po is its initial amount, r is the growth rate and t is the time.

We know after t=32 days, the population has increased by 309%. Being the original population P the 100%, then the population reached 309+100= 409%.

Substitute the given values into the model function:

[tex]409\%P_o=100\%P_o(1+r)^{32}[/tex]

Simplifying:

[tex]4.09=(1+r)^{32}[/tex]

We need to solve for r. Taking the 32nd root:

[tex]\sqrt[32]{4.09}=\sqrt[32]{(1+r)^{32}}[/tex]

Simplifying:

[tex]1+r=\sqrt[32]{4.09}=1.045[/tex]

Solving:

[tex]r=1.045-1\Rightarrow r=0.045[/tex]

r=4.5% daily