Step 1:
The first step to converting 400086.578889 to a fraction is to re-write 400086.578889 in the form p/q where p and q are both positive integers. To start with, 400086.578889 can be written as simply 400086.578889/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 400086.578889, which in this case is 6. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 400086.578889/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 400086.578889/1 each by 1000000:
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 400086.578889 as a fraction:
800173/2 / 1