a. (3 points) Using lapplyO , print the average Petal.Length by Species (only 1.5 points if dplyr' is used instead). Which species has the longest petals on average? b. (3 points) Using base R, remove all the rows related to the species setosa (only 1.5 points if dplyr' is used instead). If you do not know how to do this, use the original dataset and keep all the rows to obtain credit for the next question. c. (3 points) Using ggplot2, create a scatter plot of Fetal. Length (on the y axis) and Petal.1.-.Iidth . Use a third aesthetic (e.g. color, shape, etc) to include the variable Species in the same plot. Comment on direction of the relationship and on the role of the variable Species. d. (2 points) Consider the following linear model's results. Comment on the signicance of the predictors included in the model and say which ones are more important