# Relative rate of growth question??

• Nov 6th 2010, 11:08 AM
generalsnake
Relative rate of growth question??
The problem says to use the formula P=P1e^(kt) to fill in the missing vales of k. And P=pop. in the later year, P1=pop. earlier in the year, k=relative growth rate of world pop. per year,t=number of years between the two successive date.The first value is shown k=.28 for 1650. That plus the table below is all the info it gives me.How do I find k for the other years???

Year World population in millions. Relative rate of growth(percent/year)

1650 550 .28
1750 725 k
1850 1175 k
1900 1600 k
1950 2556 k
1980 4458 k
1999 5996 k
• Nov 7th 2010, 05:18 AM
CaptainBlack
Quote:

Originally Posted by generalsnake
The problem says to use the formula P=P1e^(kt) to fill in the missing vales of k. And P=pop. in the later year, P1=pop. earlier in the year, k=relative growth rate of world pop. per year,t=number of years between the two successive date.The first value is shown k=.28 for 1650. That plus the table below is all the info it gives me.How do I find k for the other years???

Year World population in millions. Relative rate of growth(percent/year)

1650 550 .28
1750 725 k
1850 1175 k
1900 1600 k
1950 2556 k
1980 4458 k
1999 5996 k

I would suggest you post the question exactly as worded.

Also it is unlikely that k ever had a value of 0.28 (which is 28% growth per year) are you confusing percentages with numbers?

CB
• Nov 7th 2010, 07:59 AM
generalsnake
Quote:

Originally Posted by CaptainBlack
I would suggest you post the question exactly as worded.

Also it is unlikely that k ever had a value of 0.28 (which is 28% growth per year) are you confusing percentages with numbers?

CB

alright it says exactly this
• Nov 7th 2010, 08:36 AM
CaptainBlack
Quote:

Originally Posted by generalsnake
alright it says exactly this

It tells you how to find k, all you need is the starting population the final population and the time.

CB
• Nov 7th 2010, 04:12 PM
generalsnake
Quote:

Originally Posted by CaptainBlack
It tells you how to find k, all you need is the starting population the final population and the time.

CB

I don't get how it works though because it says Po=earlier in the year
and P=later in the year, but I am only given one population for the whole year. And I am supposed to find the rates in the years, not just a year. I tried plugging in the time between the dates but I get some HUGE numbers that surpass the populations that are given.
• Nov 7th 2010, 06:57 PM
CaptainBlack
Quote:

Originally Posted by generalsnake
I don't get how it works though because it says Po=earlier in the year
and P=later in the year, but I am only given one population for the whole year. And I am supposed to find the rates in the years, not just a year. I tried plugging in the time between the dates but I get some HUGE numbers that surpass the populations that are given.

NO it does not say that it says P0 in the earlier year and P in the later year. So the first k is:

k=(1/(1750-1630)) \ln(725/550)

and what goes in the first blank is 100 times this to make it a % groeth per year.

CB
• Nov 7th 2010, 07:07 PM
generalsnake
Quote:

Originally Posted by CaptainBlack
NO it does not say that it says P0 in the earlier year and P in the later year. So the first k is:

k=(1/(1750-1630)) \ln(725/550)

and what goes in the first blank is 100 times this to make it a % groeth per year.

CB

oh! thank you. I don't know why but I kept seeing earlier in the year, so I had no idea how to solve it (Wondering).