Loading…
The core idea, one worked example, and short practice.
Learn step-by-step with practice exercises built right in.
A scatterplot is a graph made of dots. Each dot is one thing that got measured twice, like a student's study hours and that same student's test score.
A line of best fit is a straight line drawn through the middle of the dots to show their general direction.
Read the dots from left to right. Rising dots mean a positive association: as x goes up, y goes up. Falling dots mean a negative association: as x goes up, y goes down.
The line comes with an equation like y = 2x + 5. The number in front of x is the slope, and it says how much y changes each time x goes up by 1. The number added at the end is the y-intercept, the predicted y when x is 0.
To predict, put the number in for x, multiply, then add.
Review key concepts with our flashcard system
Explore more SAT Prep topics