Step 1:
The first step to converting 3615.9920721585 to a fraction is to re-write 3615.9920721585 in the form p/q where p and q are both positive integers. To start with, 3615.9920721585 can be written as simply 3615.9920721585/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 3615.9920721585, which in this case is 10. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 3615.9920721585/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 3615.9920721585/1 each by 10000000000:
Step 3:
Now the last step is to simplify the fraction (if possible) by finding similar factors and cancelling them out, which leads to the following answer for 3615.9920721585 as a fraction:
455615/126 / 1