In a high school science class, a test is worth three times as much as a quiz. What is the student’s average grade?

Test scores: 85, 92
Quiz scores: 82, 75, 95

1 answer

To find the student's average grade, we first need to determine the total scores and the total weight for both the tests and the quizzes.

Step 1: Calculate the total score for the tests. The test scores are 85 and 92.

\[ \text{Total Test Score} = 85 + 92 = 177 \]

Step 2: Determine the total score for the quizzes. The quiz scores are 82, 75, and 95.

\[ \text{Total Quiz Score} = 82 + 75 + 95 = 252 \]

Step 3: Calculate the total weight of the tests and quizzes. Since each test is worth three times as much as each quiz, we can express the weights as follows:

  • Each test has a weight of 3.
  • Each quiz has a weight of 1.

Thus, for two tests, the total weight for tests is:

\[ \text{Total Weight for Tests} = 2 \times 3 = 6 \]

And for three quizzes, the total weight for quizzes is:

\[ \text{Total Weight for Quizzes} = 3 \times 1 = 3 \]

Step 4: Calculate the total combined weight. \[ \text{Total Weight} = 6 + 3 = 9 \]

Step 5: Calculate the total weighted score. To find the total weighted score, we combine the weighted test score and quiz score:

\[ \text{Weighted Test Score} = 177 \times 3 = 531 \]

\[ \text{Weighted Quiz Score} = 252 \times 1 = 252 \]

Adding these together gives us the total weighted score:

\[ \text{Total Weighted Score} = 531 + 252 = 783 \]

Step 6: Calculate the average grade. Now, we can calculate the average by dividing the total weighted score by the total weight:

\[ \text{Average Grade} = \frac{\text{Total Weighted Score}}{\text{Total Weight}} = \frac{783}{9} \approx 87 \]

Therefore, the student's average grade is approximately 87.