Final answer:
To pass the course with a 'C' or better, Trent needs to score at least 65 on the final exam.
Step-by-step explanation:
To pass the course with a 'C' or better, Trent needs an overall score of 70 or better. The average of the three chapter tests makes up 40% of the course grade, homework accounts for 20% of the grade, the project accounts for 20%, and the final exam accounts for 20%. To calculate the overall average, we need to find the weighted average of each component. 
Let's assume the final exam score as x. The weighted average can be calculated as follows: 
0.4 * ((69 + 88 + 73) / 3) + 0.2 * 63 + 0.2 * 69 + 0.2 * x = 70 
Simplifying the equation, we get: 
0.4 * 76.66 + 0.2 * 63 + 0.2 * 69 + 0.2 * x = 70 
30.664 + 12.6 + 13.8 + 0.2x = 70 
57.064 + 0.2x = 70 
0.2x = 12.936 
x = 12.936 / 0.2 
x = 64.68 
To pass the course with a 'C' or better, Trent needs to score at least 65 on the final exam.