The Mauna Loa Observatory, located at 11,000 feet elevation in the middle of the Pacific Ocean, sits in a prime spot for measuring carbon dioxide levels in the atmosphere without local contamination. Operated by the National Oceanic and Atmospheric Administration's Climate Monitoring and Diagnostics Laboratory, the observatory has been measuring CO_{2} levels (in parts per million) since 1958.

Monthly measurement data for 1958 through January, 2008 are given in this **TI-Nspire™** file to download using Mauna Loa Data.

**Question 1:** Using these data, develop a mathematical model to predict the CO_{2} level for a month between 1995 and 2008.

**Question 2:** Now use your mathematical model to predict the CO_{2} level for October 2008. Explain clearly how you used your mathematical model to arrive at your prediction.

You should give enough detail in your solution that someone else could read your solution, follow your methodology, and come up with a similar mathematical model for a different year/month.

**Extra:** Find a mathematical model using the data from 1958 through 1995. What does that model predict for the CO_{2} level for October 2008? What's going on?

Use the **submit** link below to get hints and also chances to revise.