Solution
- 68% of the students in the class scored lower than
![\begin{gathered} \mu+\sigma \\ \text{where,} \\ \mu=\operatorname{mean} \\ \sigma=\text{standard deviation} \\ \\ \mu+\sigma=84+17.4=101.4 \end{gathered}]()
- That is, 68% of students scored lower than 101.4
- 95% of the students in the class scored lower than

- This means that 95% of the students scored lower than 118.8
- This implies that roughly 5% of students get a score higher than 118.8.
- 120 is a score that even less that 5% of the students would score, all things being equal.
- Thus, it definitely would be unusual for a student to score 120 on the exam
Final Answer
It would be unusual for a student to score 120 in the exam.