The authors of the paper “Flat-footedness is Not a Disadvantage for Athletic Performance in Children Aged 11 to 15 Years” (Pediatrics [2009]: e386–e392) studied the relationship between y 5 arch height and scores on a number of different motor ability tests for 218 children.

They reported the following correlation coefficients:

Motor Ability Test Correlation between Test Score and Arch Height Height of counter movement jump 0.02 Hopping: average height 0.10 Hopping: average power 0.09 Balance, closed eyes, one leg 0.04 Toe flexion 0.05

a. Interpret the value of the correlation coefficient between average hopping height and arch height.

What does the fact that the correlation coefficient is negative say about the relationship? Do higher arch heights tend to be paired with higher or lower average hopping heights?

b. The title of the paper suggests that having a small value for arch height (flat-footedness) is not a disadvantage when it comes to motor skills. Do the given correlation coefficients support this conclusion?
Explain.