Step 1:
The first step to converting 171578.78103851 to a fraction is to re-write 171578.78103851 in the form p/q where p and q are both positive integers. To start with, 171578.78103851 can be written as simply 171578.78103851/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 171578.78103851, which in this case is 8. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 171578.78103851/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 171578.78103851/1 each by 100000000:
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 171578.78103851 as a fraction:
686315/4 / 1