• Problem:
A student gain an average score of at least 92 on five 100 point exams to earn a grade of A in a tracticular course. If the student's score on the first four examination are 99, 92, 85, and 90, what must be his score on the fifth exam to get a grade A?
• Given:
[tex]\tt Scores: \\ \tt99 \\ \tt92 \\ \tt85 \\ \tt90[/tex]
• Solution:
✓To get the average score, you need to add all the scores and divide it to the number of scores.
✓The sign we'll use is greater than or equal to 92 since the phrase used is at least 92.
✓Suppose that the fifth score is x.
[tex] \tt\frac{99 + 92 + 85 + 90 + x}{5} \geqslant 92 \\ [/tex]
[tex] \tt\frac{366+ x}{5} = 92 \\ [/tex]
[tex] \tt366 + x = 92(5) \\ [/tex]
[tex] \tt366 + x = 460[/tex]
[tex] \tt x = 460 - 366[/tex]
[tex] \tt x = 94[/tex]
• Answer:
✓Ninety-four must be his score on the fifth exam to get a grade A.
