Understanding SAT Math (Part 3 of 8): Linear Models

A Linear Model uses a linear equation to describe the relationship between two real world properties.

A simple example might be a child’s height versus their age. If after reaching a height of 2ft, a child’s height increased by a constant number of inches each year, it could be described by a linear model.

That equation might look like this: H(eight) = 2.2A(ge) + 24

To solve linear model questions, a student must first identity the Rate of Change - the slope of the linear equation - and get clear on what it means in the context. In this height versus age equation, the slope of the line is 2.2. In this context that means that for every year the child ages, they are expected to grow 2.2 inches in height.

In almost every case, the SAT question will be based on understanding the rate of change. A question might be, “How much taller will the child be in 3 years?”, or simply, “What does 2.2 represent in the equation?”

Linear Model questions are found mostly toward the end of math sections - sometimes the last question in a section. They are expected to be challenging! But once a students determines the slope and understands what it means, they’re rather simple to solve and a good opportunity to get points that many other students will not.

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