Step 1:
The first step to converting 172209228.78819 to a fraction is to re-write 172209228.78819 in the form p/q where p and q are both positive integers. To start with, 172209228.78819 can be written as simply 172209228.78819/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 172209228.78819, which in this case is 5. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 172209228.78819/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 172209228.78819/1 each by 100000:
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 172209228.78819 as a fraction:
172209228/1 / 1