John Henry, the owner of the Red Sox would like to know the success of an advertising campaign for Sox memorabilia to be called "Fangs for the Memories" after trading away one of his best players. Henry has hired various students to forecast sales for the first two quarters of 2023. This is the sixth year of the advertising campaign. Hence they have six years of quarterly data (2017 Ql to 2022 Q4) to make their forecast.

The various groups use the will the following models:

Model 1 (Steve, Pat, Wei, Landon, Jiaqi): A simple linear trend model

Model 2 (Dan, Betsy, Nick, Michelle, Eric): A model with dummy variables to account for seasonality

Model 3 (Kaylee, John, Zach, Evan, Connor): A model with both dummy variables to account for seasonality and trend.

Question:

Evaluate the assumptions of OLS satisfied