How many parties match the canididates listed as howard baker, sr. (r) 68.9% boyd w. cox (d) 31.1%?
create table table_1342149_42 (party varchar, candidates varchar, PRIMARY KEY (party))
select count(party) from table_1342149_42 where candidates = "howard baker, sr. (r) 68.9% boyd w. cox (d) 31.1%"