This is a TI-84 activity that uses Mathematical Modeling and Climate Change data. Here is where you can get the data for a TI-84 or TI-84 CE: LEDCOST program. You can get the student sheet here: LED Lighting Cost Student and the teacher notes and solutions here: LED Lighting Cost Teacher. Or you can get all 3 files in a zip folder here: LED Lighting Cost All Files.

Student pdf:

LED01

LED02

Teacher pdf

LED03

LED04

LED05

LED06

LED07

LED08