Question

A social worker examines the level of aggression (measured on a 100-point scale) of four groups of individuals before they begin anger management classes. Using the weighted mean, determine the overall mean level of aggression for all four groups.
Group 1 82; 15
Group 2 87; 12
Group 3 93; 22
Group 4 79; 71

Answer 1

For this solution, we are assuming that the 1st number listed for each group is the mean aggression for that group, and the 2nd number is the number of participants of that group. 1. Find the total number of participants: 15 + 12 + 22 + 71 = 120 participants across all 4 groups 2. Find the total number of aggression points (group mean * group participants): 82(15) + 87(12) + 93(22) + 79(71) = 9929 total aggression points 3. Divide total aggression points by number of participants to find overall mean: 9929/120 = 82.742 or approximately 83.