Answer:
The overall score is 75.6
Letter grade is C
Explanation:
The question has missing details (See comment section for complete question).
From the complete question, we have:
Proportion:




Scores




Solving (a): The overall score
To do this, we simply calculate the mean of the given data.
The mean is calculated by multiplying each proportion by the scores..
So, we have:



Solving (b): The letter grade
From the question, we have:



The overall score falls in the following category:

Because:

Hence, the letter grade is C