91影视

• The marks obtained by the student in five regular tests are 63, 91, 88, 84, and 79. The score of 86 was earned on the final exam and 90 on class projects, resulting in a combined grade of 70.
• The proportion of weight from all exams is 60% from the final grade, 10% from the final exam, 15% from the project count, and 15% from the homework count.

Letx be the score of students in different exams or projects.

The associated weights for each exam are represented by w.

The weighted mean formula is stated as follows.

$\stackrel{炉}{x}=\frac{鈭�\left(w脳x\right)}{鈭�w}$

Here, 60% weightage is given to the five regular tests, that is, the average of the test scores.

The average of five test scores is computed as follows.

$$\begin{gathered} {\stackrel{炉}{x}}_R=\frac{鈭�x_i}{n} \\ =\frac{63+91+88+84+79}{5} \\ =\frac{405}{5} \\ =81 \end{gathered}$$

The weights associated with the scores are tabulated as follows.

Substitute the values in the formula.

$$\begin{gathered} \stackrel{炉}{x}=\frac{鈭�x脳w}{鈭�w} \\ =\frac{81脳0.6+86脳0.1+90脳0.15+70脳0.15}{0.6+0.1+0.15+0.15} \\ =\frac{48.6+8.6+13.5+10.5}{1} \\ =81.2 \end{gathered}$$

Thus, the weighted average is 81.2.

Assume the following grade criteria.

Thus, the letter grade earned by the student is B.