Paul and his friends average their test grades and find that the average is 95. The teacher announces that the average grade of all of her classes is 83. Why are the averages so different?

Nancy hears a report that the average price of gasoline is $2.82. She averages the prices of stations near her home. She finds the average price of gas to be $3.03. Why are the averages different?

Carol wants to find out the favorite foods of students at her middle school. She asks the boys’ basketball team about their favorite foods.

Dallas wants to know what elective subjects the students at his school like best. He surveys students who are leaving band class.

To choose a sample for a survey of seventh graders, the student council puts pieces of paper with the names of all the seventh graders in a bag, and selects 20 names.

Members of a polling organization survey 700 of the 7,453 registered voters in a town by randomly choosing names from a list of all registered voters. Is their sample likely to be representative?

Joey wants to find out what sport seventh grade girls like most. He asks girls, “Is basketball your favorite sport?”

Jae wants to find out what type of art her fellow students enjoy most. She asks her classmates, “What is your favorite type of art?”