Michigan State University - Diagnostic Exam

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3.3

  •   The population of a given city was 3 million in 1990 and was increasing at a rate of 2.5% per year. Which of the following equations describes the population P (in millions) of the city t years after 1990?

    a)  t P = 3 (1.025 ) b)  t P = 3(0.025) c)  t P = (3(1.025))
       
    d)  P = (3 (0.025 ))t e)  P = 3.025t

Solution:

The table below gives the population at the end of each of the first few years.

t 0 1 2 3
P 3(1 + 0.025)0 3(1 + 0.025)1 3(1 + 0.025)2 3(1 + 0.025)3

It follows that the population can be modeled using the formula P = 3(1.025)t .

Diagnostic:

If you miss this question please review exponential models.

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July 15, 2008