First L.

asked • 05/19/18

A pop. of sea monkeys has 74. They increase by 8% each month. If none die, what is total after 1 year?

I’m pretty sure it is a geometric series and it is supposed to be finding the sum.

1 Expert Answer

By:

Arturo O. answered • 05/19/18

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First L.

Actually I figured it out it was using sigma but thank you
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05/19/18

Arturo O.

Why was this answer down-voted?  The solution is correct.  The down-vote is frivolous and unjustified.
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05/19/18

First L.

No it was not I tried it and didn’t get the right answer but the equation I got was right I down-voted your answer because it was wrong??
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05/19/18

First L.

Your solution was frivolous and unjustified 
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05/19/18

Arturo O.

My solution is correct.  This problem represents exponential growth, since at the end of each month, the population is 8% higher than at the start of the month, which is an increase by a factor of 1.08 each month.  That means that after t months, the population has increased by a factor of (1.04)t, above the initial population of 74.  So after t months,
 
P(t) = P0 (1.08)t = 74 (1.08)t
 
Then after 12 months,
 
P(12) = 74 (1.08)12,
 
as in my solution.  Read up on exponential growth and see that my solution and explanation are correct.  The down-vote is frivolous and unjustified.
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05/20/18

Arturo O.

I meant to say 1.08 instead of 1.04 in my comment above.
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05/20/18

First L.

Okay but I was asking for geometric series it isn’t increasing by 1.08 it is just .08 and it is the sum and I got the right answer an yours was wrong sorry but get over it thank you for trying to help :)
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05/20/18

Arturo O.

My answer is not wrong.  The problem statement says it increases by 8% each month, which means it increases by a factor of 1.08 each month. 
 
x + (8% of x) = 1.08x
 
That is exponential growth, and it is correctly represented by the equation
 
P(t) = P0 (1.08)t
 
As I said before, read up on exponential growth and see that it applies to this problem.
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05/20/18

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