The income distribution in a county is a normal distribution with a mean income of $10,000. The top 2.5% of the wage earners ear
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Answer:
<em>C. 3.8 years</em>
Step-by-step explanation:
<u>Exponential Growth </u>
The natural growth of some magnitudes can be modeled by the equation:
Where P is the actual amount of the magnitude, Po is its initial amount, r is the growth rate and t is the time.
The actual population of deer in a forest is Po=800 individuals. It's been predicted the population will grow at a rate of 20% per year (r=0.2).
We have enough information to write the exponential model:
It's required to find the number of years required for the population of deers to double, that is, P = 2*Po = 1600. We need to solve for t:
Dividing by 800:
Taking logarithms:
Dividing by log 1.2:
Calculating:
t = 3.8 years
Answer: C. 3.8 years