12. what does the author say in the section “the unanswered question” about the
definitive proof of why friday the 13th is the unluckiest day of all?

13. what movie and novel provided another theory for why friday the 13th is so
unlucky?

14. what reason does katharine kurtz give for friday the 13th for being unlucky?
what does the of the article claim about her theory?

15. how much documentation of a superstition associated with friday the 13th
existed before the 19th century? what proof does the author offer to support his
assertion?