Question

Poindexter examined the relationship between the quality of sneakers worn by volleyball players and their average number of points scored per game, making a two-tailed prediction with α = .05. Studying 20 people who owned sneakers of good to excellent quality, he computed r = +.41. Without further ado, he immediately claimed to have supports for the notion that better quality sneakers are related to better performance on a somewhat consistent basis.

Do you agree with his statement? If you disagree, what should he conclude about the relationship? Include the statistics.

What statistical principles should Poindexter be concerned with?

Answer 1

Here, N=20, and r = 0.41

Degrees of freedom= N-2

=18

From the critical value table at alpha=0.05, and df=18,

r(critical) = 0.444

As the observed value of r(0.41) lies between the critical values of r(-0.444,+0.444) , we can conclude that r is not significant. Hence, we can reject the claim that  better quality sneakers are related to better performance on a somewhat consistent basis.