Answer:
stratified random sampling technique
Already answered here: brainly.com/question/26807124
Answer: r=-2
Step-by-step explanation:
5r=(−3)(r)+(−3)(3)+−7
5r=−3r+−9+−7
5r=(−3r)+(−9+−7)
5r=−3r+−16
5r=−3r−16
5r+3r=−3r−16+3r
8r=−16
8r/8 = -16/8
r=-2
