Alaska has the nation's highest salary of public school teachers at $43,970 and tops other states in per-pupil expenditure, the National Education Assn. said. The NEA gave state-level data on an array of educational topics in its annual research publication, "Rankings of the States." Following Alaska in public school teacher salary for 1986-87 was $33,797 for the District of Columbia, $32,000 for New York, $31,500 for Michigan and $31,219 for California. South Dakota was last at $18,781. The nation's average teacher salary was $26,551. Also, Alaska had the highest per-pupil expenditure at $8,842. The national average was $3,983. Utah was last at $2,455.