Before Buying That Car...Consider Using Linear Regression

How can linear regression be used in "the real world?"  8th grade algebra students at Tidwell
Middle School were given a scenario that asked them to answer this question.  Given a list of prices for used cars, groups of students used linear regression to find out if specific offers were reasonable based on their data. Using Google docs, groups collaboratively wrote a letter explaining whether the price was reasonable, how they found their answers, and made a new personal offer on the car.

Alyssa, Maggie, and Ethan enjoyed this particular project and comment on the learning process. "First, we used the list of prices for a car to make a scatterplot and find the line of best fit, " described Ethan. " We all were doing research and completing the work at the same time on the same document.  While I was doing research, Chloe found an online program that would help us create the graph. Then, we had to decide whether the price given was reasonable."  Ethan adds, “I learned that it is important to do research before making big financial decisions. In fact, I would do a little more research if I could do this project again.  I would have liked to explain using even more facts to justify the price in the letter."  Students were asked to do a lot of writing for this project.  Maggie explains, "I prefer writing in math because it is very to the point and accurate.  We are showing facts rather than expressing opinions.” 

"We used Google Docs and Google Spreadsheets for this project so that we could all work on the project at one time, explained Chloe. "Google sheets is great because it autosaves and updates for all of us." Alyssa adds, "Writing allowed us to get our ideas in order.  We explained each step and were able to write at the same time to make sure we were all on the same page."

The team receieved feebback on their letter from Mr. Horn and walked away well aware of the benefit of using linear regressions to find the best price point.

Elizabeth, Maggie, and Alyssa's Letter and Explanation
Ethan, Kennedy, and Chloe's Letter and Explanation