Why are the two answers different?

Question

I found exponential regression on Desmos for a few values:

I want to find the X value when Y is 40,000. So, when zooming in on 40,000, I see that X is around 160. But, when putting the equation:

y=7.4927(1.0695)^x

in Wolfram Alpha, I get x = 127.735. Why are the two answers different?

Thanks so much,

Ruchir

Answer 1

You are looking at the $y$ value 400,000, not 40,000!

If you solve $7.4927 (1.0695)^x = 400,000$ numerically, you should get $127.735$, just like the answer from Wolfram Alpha.