A newspaper article is summarized: According to a new study, teachers may be more inclined to give higher grades to students, hoping to gain favor with the university administrators who grant tenure. The study examined the average grade and teaching evaluation in a large number of courses given in 1997 in order to investigate the effects of grade inflation on evaluations. " I am concerned with student evaluations because instruction has become a popularity contest for some teachers, " said Professor Smith, who recently completed the study. Results showed higher grades directly corresponded to a more positive evaluation. The last statement above means the study found that:_________.
a) Higher course grades are positively associated with teaching evaluation
b) Teaching evaluation is negatively associated with course grade
c) There was a perfect positive correlation between course grade and teaching evaluation
d) Each letter grade increase is associated with a 10% increase in positive evaluations for the professor.
