How did you calculate these values? Without that information, it's very hard to usefully offer a comment about them.
I confess BTW that in about 13 years of doing aeroplane performance analysis as part of my job, I've never seen any particularly good reasons to trust purely calculated values, not firmly checked against carefully obtained flight test data. I'd be equally certain that FAA would only have signed off the C172 flight manual when confirmed by flight test data.
G