An ornithologist studying the glaucous-winged gull on Puget Sound counts the number of agressive interactions per minute among a group of sea gulls during 9 consecutive minutes. The following scores resulted: 24, 9, 12, 15, 10, 13, 22, 20, 14.
Calculate
a. The mean number of aggressive interactions per minute
b. The median number of aggressive interactions per minute
c. The modal number of aggressive interactions per minute biological.