I took a professor that graded his class based on weights and not points but the class weight percentages only added up to $70\%$ not $100\%$. Below is my grades:
Quiz $10\%$ weight $\dfrac{374}{384} = 97.4\%$
HW $5\%$ weight $\dfrac{95}{199} = 47.74\%$
Test $15\%$ weight $\dfrac{144}{240} = 60\%$
Final $25\%$ weight $\dfrac{120}{200} = 60\%$
Project $10\%$ weight $\dfrac{80}{80} = 100\%$
Attendance $5\%$ weight $\dfrac{120}{120} = 100\%$
When I calculated this it amounted to a $73.04\%$ as a final grade. Is this correct or is my math assuming it was weighted out of $100\%$? If I am wrong what is my correct final? Thank you in advance.
Yes, your math is assuming the grades out of $100\%$.
For example, Quiz $10\%$ weight $\frac{374}{384}=68.17\%\not=97.4\%$. You have done your calculation for percentage as $\frac{374}{384}$ x $100$, whereas, it's supposed to be multiplied by $70$.
Similarly for all the others.