Diameter displaying wrong

Hello,

Why when I select the outer circle of my drawing, in the general information it displays 4.75" for a radius, but then when I insert a radius measurement onto the drawing it displays as 3.56"? I've done it over and over making sure I'm centered and all the way out to the outer edge. Yet, it shows the correct information to the side...  Why are some of my inches getting lost when I place a measurement?

 

Thanks!