Yahoo Answers: Answers and Comments for Math problem? [Mathematics]
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From Anonymous
enUS
Thu, 20 Feb 2020 00:21:49 +0000
3
Yahoo Answers: Answers and Comments for Math problem? [Mathematics]
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https://answers.yahoo.com/question/index?qid=20200220002149AApbg30
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From llaffer: There are a few ways you can look at this. Sin...
https://answers.yahoo.com/question/index?qid=20200220002149AApbg30
https://answers.yahoo.com/question/index?qid=20200220002149AApbg30
Thu, 20 Feb 2020 01:44:10 +0000
There are a few ways you can look at this. Since we have three points on this curve, we can set up quadratic with these three points to end up with a system of three equations and three unknowns that we can solve for. There are other possible models that we can set up, but this is the one I'll choose (it probably also depends on what type of math class you are in and what you know, etc.)
If we set up this equation:
y = ax² + bx + c
and call x the number of years after 1996 and y the populations in millions, we have the following three points:
(10, 22.684)
(5, 26.087)
(0, 30)
Putting these values into the general equation gives us these three equations:
22.684 = a(10)² + b(10) + c and 26.087 = a(5)² + b(5) + c and 30 = a(0)² + b(0) + c
Simplifying them, we get a solution for c which then we can substitute into the other two equations:
22.684 = 100a  10b + c and 26.087 = 25a  5b + c and 30 = 0 + 0 + c
22.684 = 100a  10b + c and 26.087 = 25a  5b + c and 30 = c
22.684 = 100a  10b + 30 and 26.087 = 25a  5b + 30
7.316 = 100a  10b and 3.913 = 25a  5b
We can solve both equations for b in terms of a, then substituting them into each other to get one equation with one unknown that we can solve:
7.316  100a = 10b and 3.913  25a = 5b
0.7316 + 10a = b and 0.7826 + 5a = b
0.7316 + 10a = 0.7826 + 5a
5a = 0.051
a = 0.0102
Now that we have "a", we can solve for "b":
b = 0.7826 + 5a
b = 0.7826 + 5(0.0102)
b = 0.7826 + 0.051
b = 0.8336
so our equation is now:
f(x) = 0.0102x² + 0.8336x + 30
What would the population be in 5 years? Solve for f(5):
f(5) = 0.0102(5)² + 0.8336(5) + 30
f(5) = 0.0102(25) + 0.8336(5) + 30
f(5) = 0.255 + 4.168 + 30
f(5) = 34.423
The population could be 34.423 million in the year 2001, if this model is the correct one. Again, multiple models could exist which would give you different answers.

From finnn: it is definitely 8
https://answers.yahoo.com/question/index?qid=20200220002149AApbg30
https://answers.yahoo.com/question/index?qid=20200220002149AApbg30
Thu, 20 Feb 2020 00:23:12 +0000
it is definitely 8