Question

In your chemistry class, your first 3 test scores are 78, 87 and 95. What is the lowest score you can get on the

fourth test (which is the final exam that counts as 2 exam scores) to earn at least a 90 in the class if these are
the only grades for the course?

Answer 1

The lowest score you can get on the fourth test (final exam) to earn at least a 90 in the class is 95.

Step-by-step explanation:

In order to find the lowest score you can get on the fourth test to earn at least a 90 in the class, you need to first calculate your average score for the first three tests.

The average score is calculated by adding up the scores and dividing by the number of scores, which in this case is 3. So the average score is (78+87+95)/3 = 86.67.

To earn at least a 90 in the class, you need to have an average score of 90 or higher. Since the final exam counts as 2 exam scores, you can assume it as two additional scores to be added to the average score. Let's call the lowest score on the final exam x. Then the equation becomes (78+87+95+x+x)/5 >= 90.

Simplifying this equation, we get 2x >= 450 - (78+87+95) = 190. Solving for x, we get x >= 95. So the lowest score you can get on the fourth test (final exam) is 95 to earn at least a 90 in the class.