Step 1:
The first step to converting 215720.66391772 to a fraction is to re-write 215720.66391772 in the form p/q where p and q are both positive integers. To start with, 215720.66391772 can be written as simply 215720.66391772/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 215720.66391772, which in this case is 8. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 215720.66391772/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 215720.66391772/1 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 215720.66391772 as a fraction:
431441/2 / 1