[EX03-068] Stride rate (number of steps per second) is important to the serious runner. Stride rate is closely related to speed, and a runner’s goal is to achieve the optimal stride rate. As part of a study, researchers measured the stride rate at seven different speeds for 21 top female runners.

The average stride rates for these women and the test speeds are listed in the accompanying table.

Speed, x (ft/sec) 15.86 16.88 17.50 18.62 19.97 21.06 22.11 Stride Rate, y 3.05 3.12 3.17 3.25 3.36 3.46 3.55 Source: R. C. Nelson, C. M. Brooks, and N. L. Pike, Biomechanical comparison of male and female runners, in P. Milvy (ed.), The Marathon: Physiological, Medical, Epistemological, and Psychological Studies (New York Academy of Sciences, 1977), pp. 793–807

a. Construct a scatter diagram.

b. Does the relationship of the two variables appear to be linear?

c. Find the equation of the line of best fit.

d. Interpret the slope of the equation in part

c. In other words, what are the “units” of the slope?

e. Plot the line of best fit on the scatter diagram.

f. Using the line drawn in part

e, predict the average stride rate if the speed is 19 feet per second.
g. What is the stride rate if the speed is zero? Interpret your result. Do the results make sense?
Explain.
FYI Have you tried to use the computer or calculator commands yet?