What is 3+5+7+8+2
i am only giving the brainliest answer if you respond in 5 seconds

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

Would greatly appreciate these 3 answers

Which situation is an example of an observational study?