Chapter 4, Problem 20E

Tendon transfers People with spinal cord injuries may lose function in some, but not all, of their muscles. The ability to push oneself up is particularly important for shifting position when seated and for transferring into and out of wheelchairs. Surgeons compared two operations to restore the ability to push up in children. The histogram shows scores rating pushing strength two years after surgery, and the boxplots compare results for the two surgical methods. (M. J. Mulcahey, C. Lutz, S. H. Kozen, R. R. Betz, “Prospective evaluation of biceps to triceps and deltoid to triceps for elbow extension in tetraplegia,” Journal of Hand Surgery, 28, 6, 2003)

1. a) Describe the shape of this distribution.
2. b) What is the range of the strength scores?
3. c) What fact about the results of the two procedures is hidden in the histogram?
4. d) Which method had the higher (better) median score?
5. e) Was that method always better?
6. f) Which method produced more consistent results? Explain.