1.9 Fisher's irises. Sir Ronald Aylmer Fisher was an English statistician, evolutionary biologist, and geneticist who worked on a data set that contained sepal length and width, and petal length and

width from three species of iris flowers (setosa, versicolor and virginica). There were 50 flowers from each species in the data set. 14 (a) How many cases were included in the data? (b) How many numerical variables are included in the data? Indicate what they are, and if they are continuous or discrete. (c) How many categorical variables are included in the data, and what are they? List the corre- sponding levels (categories). Photo by Ryan Claussen (http://flic.kr/p/6QTcuX) CC BY-SA 2.0 license