A mixed number is one that has an integer along with a proper fraction, so that would be (for this improper fraction):
50/12 = 4 1/6
12 goes into 50, 4 times with a remainder of 2
you get: 4 and 2/12, but 2/12 can be reduced further to 1/6
so that's how i got the answer of 4 1/6