Answer:
The cutoff for a failing score was 40,
Approximately 2.3% of the students failed.
Step-by-step explanation:
Given,
Mean, 
Standard deviation, 
Let x represents the cutoff for a failing score,
Thus, according to the question,





Thus, the cutoff for a failing score is 40,
∵ P(<-2) = 0.02275 = 2.275 % ≈ 2.3 %
Hence, Approximately 2.3 % of the students failed.