18. traumatic knee dislocation often requires surgery to repair ruptured ligaments. one measure of recovery is range of motion (measured as the angle formed when, starting with the leg straight, the knee is bent as far as possible). the given data on postsurgical range of motion appeared in th article "recon- struction of the anterior and posterior cruciate ligaments after knee dislocation" (amer. j. sports med., 1999. 189-197) 154 142 137 133122126 135 135 108 120127134 122 a. what are the values of the sample mean and sample median? b. an alternative computing formula for the nu- merator of s is: 1n using this formula, determine the sample variance of the data. hint: σχί = 1695, σχ|-222,581.