Question

I posted this question yesterday that you answered, so thank you, but how do I put this in my calculator to get this answer?

If the exponential equation of best fit is y= 2.9046(1.9798)^x, when will the population be more than 13 million?

How would I figure this out?

I already determined the population in 30 days was 2,299,989,909 which is quite far from 13 million, but that gave me the number of days to figure out. How do I figure out when they give me the answer and I have to figure out the number of days?

math - unowen yesterday at 2:53pm
y=2.9046(1.9798)^x
Solve for y=13. So:
13=2.9046(1.9798)^x
13/2.9046=1.9798^x
4.47566=1.9798^x
ln 4.47566=ln 1.9798^x=x ln 1.9798
x=2.1942355
The number of days, at that rate, would be 2.1942355
☺☺☺☺

math - Steve yesterday at 4:17pm
except you want

2.9046(1.9798)^x = 13000000
x = 22.42

Answer 1

Steve may not be online right now.

Going with his equation,
2.9046(1.9798)^x = 13000000
first divide both sides by 2.9046
1.9798^x = 4475659.299.. (keep in your display)
take log of both sides, and use your log rules
x log 1.9798 = log 4475659.299
x = log 4475659.299/log 1.9798
= 22.42.. as Steve had

by keeping the 4475659.299.. in the display, we can just continue our sequence of calculations.
I then pressed:
log
=
/
log 1.9798
=
to get the answer