In your screen shot, I don't see any cases where the appointment has a status of "approved". I do see a status of "verified". Is that the same thing? I will assume that it is, but if my assumption is wrong, the change needed will be trivial.
Add a calculation field, cVerifiedFlag, written like this:
Status = "Verified"
You could write it like this if you perfer, but the result, a 1 for verified and 0/null for all others is the same:
If ( Status = "verified" ; 1 ; 0 )
Select number as the return type.
Define a summary field, sPctVerified, to compute the "fraction of total" for cVerifiedFlag.
Note, this will return a 1 if all calls were verified and a decimal less than 1 if at least one call was not verified. I recommend percent formatting so that this reads as 100% instead of 1.