The circumference of the earth is approximately 25,000 miles. what is this number expressed in scientific notation? a) 2.5 x 10^4 b) 2.5 x 10^3 c) 25 x 10^3 d) 2.5 x 10^4

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