Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 72

Medical: Injuries The Grand Canyon and the Colorado River are beautiful, rugged, and sometimes dangerous. Thomas Myers is physician at the park clinic in Grand Canyon village. Dr. Myers has recorded (for a 5-yers period) the number of visitor injuries at different landing points for commercial boat trips down the Colorado River in both the Upper and Lower Grand Canyon (Source: Fateful journey by Myers, Becker, and Stevens).

(a) Compute the mean, median, and mode for injuries per landing point in the Upper Canyon.
(b) Compute the mean, median, and mode for injuries per landing point in the Lower Canyon.
(c) Compare the results of parts (a) and (b).
(d) The Lower Canyon stretch had some extreme data values. Compute a 5% trimmed mean for this region, and compare this result to the mean for the Upper Canyon computed in part (a).