Question

am I correct here?

Conway and Littleton distance is 6.25

Answer 1

Yes, you are right
The distance is 6.25

Answer 2

Yes you are right because 1in = 50mi 
6.25x50 = 321.5

However you can say 321.5 instead of 321.50 is the same, remembrer zeros after a coma doesn't count only if they are in the front of a number it will count.