The functionf(x)=3.1x+1.7 models the median height f(x), , in feet,xyears of sprouting. The function is the "curve of best fit", meaning that in a very specific way it best models many years worth of field data (not shown).

b) According to the model (function), what is the median height of a five-year-old Melaleuca tree? Use a calculator and round to thenearest foot. The actual median height for a five-year-old Melaleuca tree is 16.4 feet. How close is the model? We can see that an empirical model like this is close but never perfect.