There are formulas to use to calculate the least squares regression line. I am sure the formulas (long and short cut) are in your text. However, if you are allowed to use a TI-83 or 84 calculator, it will do these calculations for you by using the STAT functions.
If you need to do it by hand and your book isn't helping, the formulas are available by doing a google search. I am not allowed to copy web links here.
4.
One measure of form for a runner is stride rate, defined as the number of steps per second. A runner is considered to be efficient if the stride rate is close to optimum. The stride rate is related to speed; the greater the speed, the greater the stride rate. In a study of 21 top female runners, researchers measured the stride rate for different speeds. The following table gives the average stride rate of these women versus the speed.
(Data is from 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.)
Speed 15.86 16.88 17.5 18.62 19.97 21.06 22.11
Stride Rate 3.08 3.12 3.17 3.25 3.36 3.46 3.55
a) Interpret the slope and intercept of the LSRL in context.
b) Make a prediction of the stride rate if the speed is 19 feet per second.
2 answers
a= .0774259314
b= 1.824253865
r^2= .9917812797
r= .9958821615
y= .077x + 1.82
slope= .077 & intercept= 1.82
0.77 + 1.82 (19)= 35.35/10= 3.535
b= 1.824253865
r^2= .9917812797
r= .9958821615
y= .077x + 1.82
slope= .077 & intercept= 1.82
0.77 + 1.82 (19)= 35.35/10= 3.535
1 answer