I googled Tri-State Recommendations, and came up with this page. 

I clicked on "Additional Resources", and came up with this page. Reading in the Phosphorus and Potassium section, I conclude Ohio State recommendations are based on Mehlich3.

Under the first resource, I clicked on the link and came up with this page.

Penn State converted from Bray1 and Ammonium Acetate to Mehlich3 in the late 1980's. I recall going to a meeting where the Extension Soils Specialist presented the research on this conversion.  They did not reinvent the wheel with new basic testing using Mehlich3. Rather they gathered a bunch of soil samples and analysed them with Bray1 and Ammonium Acetate, and then analyzed them with Mehlich3.  Comparing the results, they came up with the conversion from Bray1 and Ammonium Acetate to Mehlich3.  I think that is what the third link is all about. And this also suggests to me that Ohio State is using Mehlich3 for recommendations.

Looking at your soil tests, I conclude if you had entered your soil information in your soil submittal form, they would have given you a recommendation on that page. Whether that is helpful to you.... that is for you to decide.

edit to add: language on page 8 of the Tri-State Recommendations indicates to me that the Tri-State Recommendations are based on Mehlich3 testing methodology.