Step 1:
The first step to converting 17778.378429126 to a fraction is to re-write 17778.378429126 in the form p/q where p and q are both positive integers. To start with, 17778.378429126 can be written as simply 17778.378429126/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 17778.378429126, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 17778.378429126/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 17778.378429126/1 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 17778.378429126 as a fraction:
142227/8 / 1