AMC 8 Data Analysis & Statistics 1 — Questions and Answers
Question 1: The test scores of 5 students are 72, 85, 90, 68, and 95. What is the mean score?
- 80
- 82 (Correct answer)
- 85
- 78
Correct answer: 82
The mean is (72+85+90+68+95)/5 = 410/5 = 82.
Question 2: The ages of seven children are 8, 11, 7, 9, 12, 10, and 9. What is the median age?
- 9 (Correct answer)
- 9.5
- 10
- 11
Correct answer: 9
Sorted in order: 7, 8, 9, 9, 10, 11, 12 — the middle (4th) value is 9.
Question 3: In a class, monthly books read: 5 students read 1 book, 8 read 2, 4 read 3, and 3 read 4. What is the mode?
- 1
- 2 (Correct answer)
- 3
- 4
Correct answer: 2
The mode is 2 because it appears most frequently — 8 students read 2 books.
Question 4: The high temperatures for a week were 72, 68, 75, 80, 65, 70, and 74 degrees. What is the range?
- 10
- 12
- 15 (Correct answer)
- 18
Correct answer: 15
Range = maximum − minimum = 80 − 65 = 15.
Question 5: A bar graph shows enrollment per grade: Grade 5 has 120, Grade 6 has 135, Grade 7 has 115, and Grade 8 has 130 students. What is the total enrollment?
- 490
- 500 (Correct answer)
- 510
- 520
Correct answer: 500
Total = 120 + 135 + 115 + 130 = 500 students.
Question 6: Hours studied per week by 6 students: 3, 5, 7, 4, 6, 5. What is the mean number of hours?
- 4.5
- 5 (Correct answer)
- 5.5
- 6
Correct answer: 5
Mean = (3+5+7+4+6+5)/6 = 30/6 = 5 hours.
Question 7: A survey of 30 students found: 12 chose red, 8 chose blue, 6 chose green, 4 chose yellow. What fraction chose blue?
- 4/15 (Correct answer)
- 8/15
- 1/4
- 2/15
Correct answer: 4/15
8 out of 30 students chose blue, and 8/30 simplifies to 4/15.
AMC 8 Data Analysis & Statistics 1
The test scores of 5 students are 72, 85, 90, 68, and 95.
What is the mean score?