Given the model fit3, which takes into account species as well as perchDiameter, the objective now is to test that the four lines of part (c) ii all have the same slope. That is, that the lines are parallel. You are required to test this hypothesis by forming a fourth model, a sub model of fit3, one which forces the slopes to be identical (and unspecified). fit this sub model to the data and assign the result to the R variable fit4. test the hypothesis that the lines are parallel by comparing the nested models using anova() (Important: do not test by constructing an appropriate linear hypothesis