Tate scored 5 points higher on his midterm and 13 points higher on his final than he did his first exam. If his mean score was 90 what was his score on the final exam?

Respuesta :

Answer:

Juan scored 84 points on his first exam.

Step-by-step explanation:

---- ASSUMPTIONS: First Exam = X Midterm Exam = X + 5 Final Exam = X + 13 Mean Average Score for the 3 exams above = 90 ---- SOLUTION: 90 = [X + (X + 5) + (X + 13)] / 3 90 * 3 = [X + (X + 5) + (X + 13)] 270 = 3X + 18 270 - 18 = 3X 252 = 3X 252 / 3 = X 84 = X Conclusion: Juan scored 84 points on his first exam. (See below for proof) ---- PROOF: First Exam = X = 84 Midterm Exam = X + 5 = 89 Final Exam = X + 13 = 97 Mean Average of 90 points --> [84 + 89 + 97] / 3 = 270 / 3 = 90