Step 1:
The first step to converting 331.2129 to a fraction is to re-write 331.2129 in the form p/q where p and q are both positive integers. To start with, 331.2129 can be written as simply 331.2129/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 331.2129, which in this case is 4. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 331.2129/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 331.2129/1 each by 10000:
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 331.2129 as a fraction:
15567/47 / 1