Mathematics
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OpenStudy (anonymous):
Stuck with this.. Help me!!
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OpenStudy (anonymous):
OpenStudy (anonymous):
is this correct:
a^10=150000/120000
OpenStudy (anonymous):
@Mertsj can u help me with it?
OpenStudy (mertsj):
Is the formula
\[A=A _{0}e ^{kt}\]
OpenStudy (anonymous):
yea right!
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OpenStudy (mertsj):
First we have to find the constant.
OpenStudy (anonymous):
a^t=y2/y1?
OpenStudy (anonymous):
actually the formula we are using is \[N(t)=C _{0} a ^{t}\]
OpenStudy (mertsj):
\[150000=120000e ^{10k}\]
\[1.25=e ^{10k}\]
\[\ln 1.25=10k\]
\[k=.022314355\]
OpenStudy (mertsj):
Is that what you got for k?
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OpenStudy (mertsj):
What is C_0 and a in your formula?
OpenStudy (anonymous):
ur formula is right also, a is the growth factor and C0 is called the initial value..
OpenStudy (mertsj):
\[A=120000e ^{37(.022314355)}\]
A=273999 in the year 2017
Is that what you got?
OpenStudy (anonymous):
just give me a sec..
OpenStudy (mertsj):
Then I get 1.022565182 for the growth factor.
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OpenStudy (anonymous):
yea i got the same thing
OpenStudy (anonymous):
for part a
OpenStudy (anonymous):
for b.. is it like (0.022314355-1) x 100%
OpenStudy (mertsj):
\[A=120000(1.022565182)^1=122707.8219\]
\[122708-120000=2708\]
\[\frac{2708}{120000}=2.3 % yearly increase
OpenStudy (mertsj):
b is the growth factor.
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OpenStudy (mertsj):
c is the percent annual increase.
OpenStudy (mertsj):
Are we on the same page?
OpenStudy (anonymous):
yea..
OpenStudy (anonymous):
for c is it (a-1) x 100%?
OpenStudy (mertsj):
\[2=1.022565182^{t}\]
\[t=\frac{\ln 2}{\ln 1.022565182}=31 years\]
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OpenStudy (mertsj):
Yes. It would be just what you said.
OpenStudy (anonymous):
okay
OpenStudy (mertsj):
If you round it would be 2.3 %, the same thing I got
OpenStudy (anonymous):
got it.. i am a little confused how u get the growth factor?
OpenStudy (mertsj):
\[1000000=120000(1.022565182)^t\]
\[8.333=(1.022565182)^t\]
\[t=\frac{\ln 8.3333}{\ln 1.022565182}=95\]
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OpenStudy (mertsj):
95 years after 1980=2075
OpenStudy (mertsj):
\[150000=120000a ^{10}\]
Solve that for a
OpenStudy (anonymous):
so its like a^10=1.25
OpenStudy (anonymous):
1.022...83 it got it now.. so part a and b are kinda same thing!!
OpenStudy (mertsj):
\[1.25=a ^{10}\]
\[\ln 1.25=10\ln a\]
\[\frac{\ln 1.25}{10}=\ln a\]
\[.022314355=\ln a\]
\[e ^{.022314355}=a=1.02256518\]
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OpenStudy (mertsj):
You might say that.
OpenStudy (anonymous):
okay..
OpenStudy (anonymous):
well thanks for all ur help.. :)
OpenStudy (mertsj):
yw