Answer:
A confidence interval
Step-by-step explanation:
She could construct a confidence interval that would let her be confident to a certain level of the students scores on the final, based on their scores on Exam 3.
She would have to calculate the standard deviation of the students who scored an 80. The mean is 80 so we need not calculate that.
She could then choose her level of confidence (90%, 95%, 99% are the most common), and construct an interval of scores.
