(Data file: Minn Land) Another variable in this data file is the region, a factor with six levels that are geographic identifiers. Assuming both year and region are factors, consider the two mean...

(Data file: Minn Land) Another variable in this data file is the region, a factor with six levels that are geographic identifiers.

Assuming both year and region are factors, consider the two mean functions given in Wilkinson–Rogers notation as:

(a) log(acre Price) ∼  year +  region

(b) log(acre Price) ∼ year + region + year: region Explain the difference between these two models (no fitting is required for this problem).