The fraction 3/7 is alread in the simplest form, so it isn't possible to reduce it any further.
This is a PROPER FRACTION once the absolute value of the top number or numerator (3) is smaller than the absolute value of the bottom number or denomintor (7).
The fraction 3/7 is equal to 3÷7 and can also be expressed in decimal form as 0.428571.
Hope this helps... Sorry.