Step 1:
The first step to converting 851491678.2563 to a fraction is to re-write 851491678.2563 in the form p/q where p and q are both positive integers. To start with, 851491678.2563 can be written as simply 851491678.2563/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 851491678.2563, which in this case is 4. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 851491678.2563/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 851491678.2563/1 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 851491678.2563 as a fraction:
851491678/1 / 1