Two friends plant a tree and record the height of the tree each following year to track its growth. The data can be represented by the linear model y = 4.3z +3.25, where y represents the height of the tree, in feet, and z represents the number of years since it was planted.
Based on the linear model, what is the expected height of the tree in 8 years?
3.25
4.3
31.2
37.65