FINDING THE MISSING NUMBER

Amy’s current grades for her assignments in math class are 85, 90, 95, and 80. What grade does she have to earn on her next assignment to attain an average of 90?

• 88

• 90

• 95

• 100

Betsy has scored a 94, 80, 89, 91 and 90 on her math tests. What must Betsy score on her next test to have a mean of exactly 90?

• 96

• 91

• 90

• 89

Terry scored 71, 80, and 86 on his first three history tests. What must Terry score on the fourth test to have a mean of exactly 80? 

• 80
• 83
• 85
• 88

Christine’s test scores are 86, 94, 88, 75, and 94. What does Christine need to score on the next test to have a mean score of 85?

• 90

• 73

• 94

• 100

Blake’s test scores are 86, 70, 72, 100, 96, and 80. Which score must Blake earn on his next test to have a mean grade of exactly 85? 

• 91
• 88
• 85
• 84

Keith has earned a 75%, an 86%, and an 83% on his tests so far this grading period. He wants to have an 80% average. If each test is included equally in his average, what is the lowest score that Keith could earn on the next test and keep at least an 80% average? 

• 69
• 72
• 76
• 80