From the table we notice that the student got 56 points of 70 possible from homework.
He got 75 points out of 83 from quizzes and he got 163 out of 200 from exams.
This means that we have the ratios 56/70, 75/83 and 163/200 for homework, quizzes and exams, respectively.
Now we multiply each ratio by the percent it represents of the final note to get it:
Therefore the weighted grade is 83.42 points