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.

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.

Which of these angles are supplementary? a. 100o and 90o b. 78o and 102o c. 54o and 146o d. 12o and 78o