PSAT Math Multiple-Choice Question 751: Answer and Explanation

Question: 751

What would most likely be the average of the slopes of the best-fit lines of the data if the researcher collects and plots the 50 randomly selected values 100 times?

• A. -2
• B. 0
• C. 1
• D. 3.5

Correct Answer: B

Explanation:

(B) A best-fit line is a line on the graph that shows the overall direction the points seem to be going. The best-fit lines of both of these sets would most likely be a horizontal line with a y-intercept of approximately 50. Horizontal lines have a slope of 0, so the average of the slopes of both of these lines would most likely be 0 as well.