What is my total grade average? Task 1: $\dfrac{19}{30}$ worth $20\%$ of final grade Task 2: $\dfrac{68}{80}$ worth $15\%$ of final grade Task 3: $\dfrac{19}{46}$ worth $15\%$ of final grade Task 4: $85\%$ , worth $15\%$ of final grade

Total of percentages : $20+15+15+15=65\%$

Grades, on $100$ points :

$\frac{19}{30}=\frac{63.33}{100},\frac{68}{80}=\frac{85}{100},\frac{19}{46}=\frac{41.30}{100}$ and last one is $\frac{85}{100}$

Therefore the average is $a=\dfrac{63.33*20+85*15+41.3*15+85*15}{65}=\frac{68}{100}$

Your average so far should be **68.25/100**

If you get $80\%$ on your last exam worth $35\%$ of the grade your final average will be :

$a=\dfrac{63.33*20+85*15+41.3*15+85*15+80*35}{100}=\frac{72}{100}$

Your final average would be **72.36/100**