Do you think there would be a positive correlation between a placement test score and the final grade in any given class?

Do you think there would be a positive correlation between a placement test score and the final grade in any given class? What other variables do you think would have a positive correlation with the final grade in a class? What variables would have a negative correlation with a final grade in a class? Look up a study that finds a correlation between grades and some other variable. Describe the variables, the study, the methods used, whether the correlation is positive or negative, and how this relates to your life.