Step 1:
The first step to converting 13898.421991406 to a fraction is to re-write 13898.421991406 in the form p/q where p and q are both positive integers. To start with, 13898.421991406 can be written as simply 13898.421991406/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 13898.421991406, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 13898.421991406/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 13898.421991406/1 each by 1000000000:
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 13898.421991406 as a fraction:
97289/7 / 1