Pushing economy and wheelchair-propulsion technique were examined for eight ­wheelchair racers on a motorized treadmill in a paper by Goosey and Campbell [Adapted Physical ­Activity Quarterly (1998) 15: 36–50]. The eight racers had the following years of ­racing experience:
Racing experience (years): 6, 3, 10, 4, 4, 2, 4, 7
a. Verify that the mean years of experience is 5 years. Does this value appear to adequately represent the center of the data set?
b. Verify that Σt (y –y-bar)2 = Σt(y –5)2 = 46.
c. Calculate the sample variance and standard deviation for the experience data. How would you interpret the value of the standard deviation relative to the sample mean?