4. Give examples of two variables that have perfect positive linear correlation and two variables that have perfect negative linear correlation.

"In Exercises 13-16, use the value of the correlation coefficient r to calculate the coefficient of determination r^2. What does this tell you about the explained variation of the data about the regression line? about the unexplained variation?

16. r = 0.795"

What are some advantages of the Spearman rank correlation coefficient over the Pearson correlation coefficient?

What does it mean when rs is equal to 1? What does it mean when rs is equal to ? What does it mean when rs is equal to 0?

Explain, in your own words, what rs and (rho)s represent in Example 1.

In Exercise 23, add data for a child who is 6 years old and has a vocabulary of 900 words. Describe how this affects the correlation coefficient r.

In Exercise 24, remove the data for the student who is 57 inches tall and scored 128 on the IQ test. Describe how this affects the correlation coefficient r.

In Exercise 25, remove the data for the international soccer player with a maximum weight of 170 kilograms and a jump height of 64 centimeters. Describe how this affects the correlation coefficient r.

In Exercise 26, add data for an international soccer player who can perform the half squat with a maximum of 210 kilograms and can sprint 10 meters in 2.00 seconds. Describe how this affects the correlation coefficient r.