The popular `iris` data set gives the measurements in centimeters of the variables sepal length and width and petal length and width, respectively, for 50 flowers from each of 3 species of iris. The species are Iris setosa, versicolor, and virginica. The `iris` data set is included with every R installation. i) Check the structure of the`iris` data. ii) How many variables and observations are in the data set? iii) Which variables are `numeric` type? iv) Display the first 4 rows of the data.