Here are the sample sizes and means for the four racial/ethnic groups on the Political Efficacy Index (only the 17- to 20-year-olds): Whites: n = 32, mean = 6.97 Blacks: n = 21, mean = 8.14 Hispanics:...

Here are the sample sizes and means for the four racial/ethnic groups on the

Political Efficacy Index (only the 17- to 20-year-olds):

Whites: n = 32, mean = 6.97

Blacks: n = 21, mean = 8.14

Hispanics: n = 32, mean = 6.84

Others: n = 5, mean = 4.40

Find the overall mean for all 90 respondents.