Asocial 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: mean = 82, n = 15; group 2: mean = 87, n = 12; group 3: mean = 93, n = 22, and group 4: mean = 79, n = 11

To answer this item, what needs to be done first is to determine the total of the values per group by multiplying the mean by the number of people in the group.

Group 1:    (82)(15) = 1230
Group 2:    (87)(12) = 1044
Group 3:    (93)(22) =  2046
Group 4:    (79)(11) =   869

Then, we add up the products to determine the overall total
        Overall total = 1230 + 1044 + 2046 + 869 = 5,189

Then, we divide the overall total by the total number of people in four groups
    total number of people = 15 + 12 + 22 + 11 = 60
 
         Overall mean = 5,189 / 60 = 86.48

Therefore, the answer is ~86.5.