Final answer:
The student's overall final score is 74.95 and he earned a C grade.
Step-by-step explanation:
To calculate the student's overall final score, we need to find the weighted average of each component based on their respective percentages.
Step 1: Convert the scores to their weighted values:
Midterm: 60 * 0.1 = 6
Project: 80 * 0.05 = 4
Homework: 75 * 0.45 = 33.75
Final exam: 78 * 0.4 = 31.2
Step 2: Add up the weighted values: 6 + 4 + 33.75 + 31.2 = 74.95
Therefore, the student's overall final score is 74.95.
Based on the grading scale provided, a mean score of 90 or above is an A, 80 to 89 is a B, and so on. Since the student's overall final score is below 80, he would earn a C grade.