Core Academic Skills Assessment Mathematics: Data and Statistics

Question 1

A dataset has values: 4, 7, 7, 9, 13, 15, 15, 15, 20. What is the mode?

Accepted Answer

15

Answer

The mode is 15 because it appears three times, more than any other value.

Question 2

The box plot for a dataset shows Q1 = 12, median = 18, Q3 = 26. What is the interquartile range (IQR)?

Accepted Answer

14

Answer

The IQR equals Q3 minus Q1, so 26 − 12 = 14.

Question 3

A survey finds 60% of students prefer math, 30% prefer reading, and 10% prefer science. In a class of 40 students, how many prefer reading?

Accepted Answer

12

Answer

30% of 40 = 0.30 × 40 = 12 students prefer reading.

Question 4

Which measure of central tendency is MOST affected by an extreme outlier?

Accepted Answer

Mean

Answer

The mean uses all values in its calculation, so an extreme outlier pulls it significantly away from the center.

Question 5

A scatter plot shows points clustered closely around a line going from lower-left to upper-right. This indicates:

Accepted Answer

A strong positive correlation

Answer

Points clustered tightly along an upward-trending line indicate a strong positive correlation.

Core Academic Skills Assessment Practice Test