1. ## exponential function

A city is growing at the rate of 0.5% annually. If there were 3,896,000 residents in the city in 1995, find how many (to the nearest ten-thousand) are living in that city in 2000. Use the equation f(t)=3,896,000(2.7)^0.005t

2. Originally Posted by getnaphd
A city is growing at the rate of 0.5% annually. If there were 3,896,000 residents in the city in 1995, find how many (to the nearest ten-thousand) are living in that city in 2000. Use the equation f(t)=3,896,000(2.7)^0.005t
plug in t = 5 and solve

3. I tried that but I still did not come up with the correct answer.

This is what I did:
f(t)=3,896,000(2.7)^0.005(5)

Is this right?

4. Originally Posted by getnaphd
I tried that but I still did not come up with the correct answer.

This is what I did:
f(t)=3,896,000(2.7)^0.005(5)

Is this right?
yes (but technically you should have f(5) on the left)

but yes, the value of that function is the answer. remember 0.005(5) is a power. be careful how you input this into your calculator

if you don't have a calculator with a secondary display, like a TI-89 or whatever, you have to input 2.7^[0.005(5)] first, and then multiply that answer by 3896000

5. The answer is 3,990,000 but I still do not understand how this came about. I did everything like you said and I still did not come up with this answer.

I have a TI-83 calculator.

This is what I input: 389600(2.7)^0.005(5) is this correct?

6. Originally Posted by getnaphd
The answer is 3,990,000 but I still do not understand how this came about. I did everything like you said and I still did not come up with this answer.

I have a TI-83 calculator.

This is what I input: 389600(2.7)^0.005(5) is this correct?
the answer you should get is 3993953.85 then you round that off to 3990000 since the question said to the nearest 10000

7. I did not multiply the 5 with 0.005 first. With this way I came up with 399395.

Thank you soooo much. I finally got it after 12 tries.