Step 1:
The first step to converting 3486.2089985802 to a fraction is to re-write 3486.2089985802 in the form p/q where p and q are both positive integers. To start with, 3486.2089985802 can be written as simply 3486.2089985802/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 3486.2089985802, which in this case is 10. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 3486.2089985802/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 3486.2089985802/1 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 3486.2089985802 as a fraction:
66238/19 / 1