Final answer:
Jace must score 15 points higher than his current average on the 5th exam to achieve an average of x + 3. The calculation involves setting up an equation based on the weights of the exams, leading to the answer that 15 points more than the average x is needed. The provided answer choices do not include the correct answer.
Step-by-step explanation:
The question deals with the scenario where Jace needs to score a certain number of points higher than his current average score x on his 5th exam to attain an average of x + 3 across all five exams. To figure this out, we can set up an equation based on the fact that the exams are equally weighted.
Let the score Jace needs to get on the 5th exam be y. Since the average after five exams should be x + 3 and the first four exams have an average of x, we have:
(4x + y) / 5 = x + 3
Multiplying both sides of the equation by 5 to clear the fraction gives us:
4x + y = 5x + 15
Now, we subtract 4x from both sides to isolate y on one side of the equation:
y = x + 15
Since we are asked how many points higher than x he must score, we subtract x from y:
y - x = (x + 15) - x
y - x = 15
So, Jace must score 15 points higher than his current average, x, to end up with an average of x + 3 after five exams. None of the answer options provided (a, b, c, or d) is correct.