To find the fraction of students who did not get an A on the final exam, we first need to determine the number of students who did not get an A.

Total number of students: 45
Number of students who got an A: 9

Number of students who did not get an A: $45 - 9 = 36$

Next, we express the fraction of students who did not get an A: $\text{Fraction} = \frac{36}{45}$

Now, we simplify the fraction by finding the greatest common divisor (GCD) of 36 and 45, which is 9: $\frac{36 \div 9}{45 \div 9} = \frac{4}{5}$

So, the fraction of students who did not get an A on the exam is $\frac{4}{5}$.

Would you like more details or have any questions?

Here are 5 related questions:

1. If 12 more students had received an A, what fraction of the students would have received an A?
2. What percentage of students received an A on the final exam?
3. If half of the students who did not receive an A had received a B, how many students received a B?
4. How would the fraction change if 5 more students had taken the exam but none received an A?
5. What is the decimal equivalent of the fraction of students who did not get an A?

Tip: Always simplify fractions by finding the greatest common divisor to ensure they are in their lowest terms.