SOLUTION: On Jan 1 1970 the population of Sarnia was 70000. On Jan 1 2008, the population is approximately 113000. Find the exponential growth rate of the city and what will the popul

Algebra ->  Exponents -> SOLUTION: On Jan 1 1970 the population of Sarnia was 70000. On Jan 1 2008, the population is approximately 113000. Find the exponential growth rate of the city and what will the popul      Log On


   

Question 1192876: On Jan 1 1970 the population of Sarnia was 70000. On Jan 1 2008, the population is approximately 113000.
Find the exponential growth rate of the city
and what will the population be in 2022?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
That was 38 years passage from 1970 to 2008.

70000%281%2Br%29%5E38=113000
Is this enough for you to continue and then to finish?
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log%28%2870000%2A%281%2Br%29%5E38%29%29=log%28%28113000%29%29
log%28%2870000%29%29%2B38%2Alog%28%281%2Br%29%29=log%28%28113000%29%29
4.845098%2B38%2Alog%28%281%2Br%29%29=5.0530784
38%2Alog%28%281%2Br%29%29=5.0530784-4.845098
38%2Alog%28%281%2Br%29%29=0.2079804
log%28%281%2Br%29%29=0.005473168
If use base ten, then
1%2Br=10%5E%280.005473168%29
1%2Br=1.01268
About 1%2Br=1.0127
So highlight_green%28r=0.0127%29 or 1.27 percent increase per year.