Please don’t think this is scientific, but for those who want to do the same calculation that I’m doing:
StateCutoffFor2015 = ((2014StateSICutoff - 2014SIMean) / 2014SIStdDev) * 2015StdDev) + 2015SIMean
2014StateSICutoff is the state in question available from http://www.fairtest.org/sites/default/files/NationalMerit2016CutoffRelease.pdf
2014SIMean = 141.9
2014SIStdDev = 30.7
from http://www.bernardsboe.com/UserFiles/Servers/Server_3096886/File/Jill%20Shadis/Ridge%20Counseling/Standardized%20Testing/Understanding%202014%20PSAT-NMSQT%20Scores.pdf
2015SIStdDev = 28 from @billchu2 's curve fitting http://talk.collegeconfidential.com/discussion/comment/19180539/#Comment_19180539
2015SIMean = 146 from page 11 in https://collegereadiness.collegeboard.org/pdf/2015-psat-nmsqt-understanding-scores.pdf
StateCutoffSIFor2015 = (((2014StateSICutoff - 141.9) / 30.7) * 28) + 146
There are many sources of errors in this simple model. As others have said, maybe on a different thread, there can be ± 2 from year to year for a state. Also, we are looking at the right end tail of a distribution, assuming it is normal when it might be skewed.
So, for example, for CA, using my stddev doodle, I get 220 . Using DC & outside US, 225 in 2014, the highest, I get 222. For Illinois, I get 213.
This is just an exercise, probably not that accurate. Please don’t think it makes or breaks your chances.