There are 36 bottles of milk in 3 cases. which unit rate represents this ratio?
a. 3 bottles per case
b. 12 bottles per case
c. 18 bottles per case
d. 36 bottles per case

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