Question 377680
This is the model showing the percentage of Americans with heart disease who are "x" years old: 
90/1+271e^-0.122x
At what age will the percentage of Americans with heart disease be 70%?
I'm thinking it works like this: 
0.7 = 90/1+271e^-0.122x
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Try this:
70 = 90/[1+271e^-0.122x]
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1 + 271e^-0.122x = 90/70 = 1.2857
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271e^-0.122x = 0.2857
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e^-0.122x = 0.004744
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Take the ln to get:
-0.122x = -5.3508
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x = 43.86 yrs old
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Cheers,
Stan H.