# [SOLVED] I need Help Please???

• Jun 22nd 2006, 06:59 AM
santos
This is reaally important.

The formula P=Po(1+r)^n gives the population P at the end of an n-year time period, where Po is the initial population and r is the average anual growth rate. The U.S. Population grew from 248.7 million in 1990 to 294.4 million in 2004 (US Census Bureau). Find the average anual rate of growth for the US population for that period.

I have tried the numbers in the formula, but i don't know how to solve it. Quick Responses with the answer is greatly appreciated. Thank You.
• Jun 22nd 2006, 07:49 AM
malaygoel
Quote:

Originally Posted by santos
This is reaally important.

The formula P=Po(1+r)^n gives the population P at the end of an n-year time period, where Po is the initial population and r is the average anual growth rate. The U.S. Population grew from 248.7 million in 1990 to 294.4 million in 2004 (US Census Bureau). Find the average anual rate of growth for the US population for that period.

Quick Responses are greatly appreciated. Thank You.

It is very simple. You have the formula, just plug in the values.
p=294.4
Po=248.7
n=14

Keep Smiling
Malay
• Jun 22nd 2006, 08:28 AM
Soroban
Hello, santos!

Read the problem again . . . and ignore any extraneous information.

Quote:

The U.S. Population grew from 248.7 million in 1990 to 294.4 million in 2004.

Find the average annual rate of growth for the US population for that period.
The population grew from 248.7 million to 294.4 million from 1990 to 2004.

That's an increase of $294.4 - 248.7 \,=\,45.7$ million in $14$ years.

Therefore, the average growth is: . $\frac{45.7}{14} \:\approx \:3.26$ million per year.
• Jun 22nd 2006, 08:49 AM
malaygoel
Quote:

Originally Posted by Soroban
Hello, santos!

Read the problem again . . . and ignore any extraneous information.

The population grew from 248.7 million to 294.4 million from 1990 to 2004.

That's an increase of $294.4 - 248.7 \,=\,45.7$ million in $14$ years.

Therefore, the average growth is: . $\frac{45.7}{14} \:\approx \:3.26$ million per year.

Hello Soroban!
In this question, average growth rate is r which appears in the formula in first post of this thread(read carefully)
Keep Smiling
Malay
• Jun 22nd 2006, 09:55 AM
Soroban
Hello, Malay!

Got it . . . thanks.
(Another blunder . . . *blush*)
• Jun 22nd 2006, 09:59 AM
Jameson
So like malaygoel said, you have all the info you need.

$P=P_{0}\left(1+r^n\right)$

Using your numbers, $294.4=248.7\left(1+r^{14}\right)$

Solve for r.