1. For each situation, explain why data are collected from a sample and not a census. a) To test the quality of milk.

b) To find the percent of Grade 7 students who know the multiplication tables.

c) Rita researched accident statistics in her community. She learned that, in the past year,
30 people were injured in car accidents and 10 people were injured in motorcycle
accidents. Rita inferred, “It is safer to ride a motorcycle than it is to drive a car.”
Is Rita’s inference valid? Explain.