what was the hypothesis or purpose)?

This is usually found at the beginning of the article.   Usually the hypothesis or statement of a problem appears at the end of the review of the literature, most often in the last or next to last paragraph.  The words that indicate  that it is a hypothesis are, "We will examine. . ." or "Our  hypothesis is . . ."  In a statement of a problem, the researcher may say, "We plan to  see if a relationship…," "We proposed to observe…," or  "The problem we proposed to study…"