If Statement Help Please

I had this solved however I made a mistake! The ceiling has to occur before the if statement. One of the values is 47.59 and it is first seen as less than 48 then it is rounded to 48 using the ceiling. I need it to be rounded to 48 then seen as 48 therefore rounded to 50! Below is what I have can you please help!

=CEILING(IF(AND(I11>47.99,I11<50),50,I11),1)

I am creating a gradebook which calculates grades and basically if you have a 48 or 49 final grade you will receive a 'mercy pass' and therefore given a 50. The grade is in cell L4 and the final is in cell J4.

If they have a grade of 51 or above it will remain at that grade. My problem is keeping their current grade. Anyone help create this formula please ?

47.99 or below = the same value
48 to 49.99 = 50
50+ = same value