This Instructional Activity is a part of the Lesson 1, Unit 9, Grade 8. In the previous activity, students drew a line that best fit the latitude-temperature data and found the equation of this line. The line is a mathematical model of the situation. In this lesson, they will be using their model to make predictions about temperatures in cities that were not included in the original data set. In the next activity, they will also interpret the slope of the line and the intercepts in the context of this situation. This leads into a discussion of the limitations of the mathematical model they developed.