You need all string variables.
You'll probably be happier with ALL CAPS, too.
Code:
10 home
20 input "What state do you live in?";a$
30 if a$="Ohio" then goto 50
40 if a$<>"Ohio" then goto 10
50 input "Correct! Type 'next' for the next question.";b$
60 if b$="next" then goto 70
70 home
80 input "What month is this?";c$
90 if c$="February" then goto 110
100 if c$<>"February" then goto 70
110 print "Correct! Thus concludes this program."
120 end