Since the list of grades is not provided, we cannot calculate the exact frequencies. However, if the list were available, the final answer would be presented as follows:
- Grade C frequency = \(\boxed{\text{C frequency}}\)
- Grade A frequency = \(\boxed{\text{A frequency}}\)
- Grade B frequency = \(\boxed{\text{B frequency}}\)
- Grade F frequency = \(\boxed{\text{F frequency}}\)
Please provide the list of grades to proceed with the calculations.