Mychances.net ... Is this an accurate prediction?

3.5 unweighted GPA is just below average for Clemson entering freshmen, and Clemson also doesn't consider extracurricular activities *at all* in admissions decisions. The competition for out-of-state slots is also pretty intense. All those are factors against you. You mentioned you have a decent composite SAT score, but one of the scores you gave is 520. You didn't indicate which section you got a 520 in, but if it's math then that will definitely be a huge strike against you at Clemson in general, but may be mitigated or exacerbated depending on what your intended major is. IOW if you're trying to get into an English major, your math score may not make as much of a difference; if you're trying to major in Engineering or Architecture or something like that, though, a 520 math score will sink you. I suspect all those factors are what made your Clemson percent come in so low. However, the only real way to find out is (a) speak to a Clemson admissions counselor, (b) apply! :) Clemson does take a good proportion of out-of-state students so it's certainly not impossible to get in from Machusetts.