Kami has an average of 64% in her class. School ends soon and she would like to raise her grade to a 74%.She has 2 tests left and tests counts as 80% of her grade, what would she have to get on the next to test to get her average up to a 74%?

Question

Kami has an average of 64% in her class. School ends soon and she would like to raise her grade to a 74%.She has 2 tests left and tests counts as 80% of her grade, what would she have to get on the next to test to get her average up to a 74%?

Answer 1

To determine what grade Kami needs to achieve on her next test, we can follow these steps:

Step 1: Calculate the current weight of Kami's average:
Since test grades count as 80% of her overall grade, the remaining 20% can be attributed to other components such as assignments or class participation.

Step 2: Calculate the weighted average required for a 74% overall grade:
Considering tests make up 80% of her grade, Kami needs to determine her desired average specifically for tests. To achieve an overall grade of 74%, her average test grade must also be 74%.

Step 3: Determine the weight of the remaining tests:
Since Kami has 2 tests left, we need to consider the weight of each test. Since tests comprise 80% of her grade, each test would weigh 80%/2 = 40%.

Now, let's calculate the required grade for Kami's next test:

Step 1: Calculate the current weight of Kami's average:
The current weight of Kami's average can be calculated by multiplying her average (64%) by the weight of the average (20%):
Current weight of average = 64% * 20% = 12.8%.

Step 2: Calculate the weighted average required for a 74% overall grade:
Since Kami wants to achieve a 74% overall grade and tests constitute 80% of her grade, the weighted average she needs for her tests is:
Weighted average for tests = 74% * 80% = 59.2%.

Step 3: Determine the weight of the remaining tests:
Since Kami has 2 tests left, each test weighs 40%.

Step 4: Calculate the required grade for Kami's next test:
To calculate the grade Kami needs to achieve on her next test, subtract the current weight of her average from the weighted average required for a 74% overall grade, and divide the result by the weight of the upcoming test:
Grade required on next test = (Weighted average for tests - Current weight of average) / Weight of next test
Grade required on next test = (59.2% - 12.8%) / 40%
Grade required on next test ≈ 46.4% / 40%
Grade required on next test ≈ 1.16

Therefore, Kami would need to achieve at least 1.16% (round up to 2%) on her next test to raise her grade to an overall average of 74%.