need help!

4. A social scientist wants to use subjects' number of hours playing sports each week to predict their score on a test of propensity to violence. Subjects who play more hours of sports tend to get lower"- scores on the test. But regressing their violence test score on their hours of sports played per week' explained only 22 percent of the total score. What 1s the correlation between their hours of sports played per week and violence test scores? Show your work/explain