AMC 8 Data Analysis & Statistics 3

Question 1

The average of 6 numbers is 12. When one number is removed, the average of the remaining 5 is 11. What number was removed?

Accepted Answer

17

Answer

15

Answer

16

Answer

18

Question 2

Five quiz scores are 62, 75, 80, 85, and 88. If the lowest score is removed, by how much does the mean increase?

Accepted Answer

4

Answer

2

Answer

6

Answer

3

Question 3

A histogram has intervals with frequencies: 0–10: 3, 10–20: 8, 20–30: 12, 30–40: 5. In which interval does the median fall?

Accepted Answer

20–30

Answer

0–10

Answer

10–20

Answer

30–40

Question 4

A data set of 8 values has a sum of 96. Three new values of 10, 12, and 14 are added. What is the new mean?

Accepted Answer

12

Answer

11

Answer

13

Answer

14

Question 5

In a box plot, Q1 = 20, median = 30, Q3 = 40, minimum = 10, maximum = 60. What is the interquartile range (IQR)?

Accepted Answer

20

Answer

15

Answer

25

Answer

30

Question 6

The mean of a data set is 15 and the median is 13. If the largest value (an outlier of 30) is removed, what is most likely true?

Accepted Answer

The mean decreases more than the median

Answer

The median decreases more than the mean

Answer

Both decrease by the same amount

Answer

Neither changes

Question 7

Students earn these scores on a 10-question quiz: five students score 6, three score 8, two score 10. What is the mean score?

Accepted Answer

7.4

Answer

7

Answer

7.6

Answer

8