4 – 15,000,000
3 – 1,350,000 * (3 * 4) = 16,200,000 <--Trying to make this 15,000,000
2 – 225,000 * (3 * 2) = 1,350,000
1 – 75,000 * (3 * 1) = 225,000
I am having difficulties trying to find a series of numbers that scale exponentially (can't be linear) to multiply by, that will allow me to reach 15,000,000 exactly from a starting point of 75,000. How do I calculate this?
So it seems to me like you want After step $i$ to have $75000 r^i$. Then after three steps you have $75000 r^3=1500000$. Then $r=\sqrt[3]{15000000/75000}\approx 5.848$. Then after the first step you get $438600$, after step 2 you have $2564932.8$, and after step 3 you have $14999727.0$.