123.4651163 or rounded to 123.47
63.3% decrease
49 - 18 = 31
31/49 = 0.63265 x 100
= 63.3 rounded to the nearest tenth of a percent

Since the first number is 1, it will remain 1 at the end. So we have to find the bottom number to the power of four.

This can be simplified to equal

Which equals to 16. So we know the final equation will be equal to
1/16
The function is never constant
Exponential/Logarithmic functions are never constant
Simply multiply the total amount by the percentage deducted in decimals.
(28,600) * (0.16667) = $4,799.67