A group of environmentalists reported the results of a study of giant armadillos inhabiting the southeastern region of Venezuela. A sample of 80 armadillos was captured and the body length (not including the tail) of each was measured (in centimeters). A MINITAB graph summarizing the data is shown below.

a. What type of graph is employed?
b. How many armadillos have body lengths between 87 and 91 centimeters?
c. What proportion of the armadillos have body lengths between 87 and 91 centimeters?
d. The dotted vertical lines on the graph show the minimum and maximum sizes of giant armadillos that can be legally captured for commercial purposes. What proportions of the captured armadillos are illegal?