One day in the school cafeteria the number of children who bought white milk was twice the number who bought chocolate milk how many cartons of each type of milk were sold if the cafeteria sold a total of 141 cartons of milk?

Aresearch study is done to find the average age of all u. s. factory workers. the researchers asked every factory worker in ohio what their birth year is. this research is an example of a census survey convenience sample simple random sample