A certain store has 3,000 employees working at its main location in a city and 100 employees working at a smaller location outside the city. The store manager will select a sample of 50 employees from all the employees to ask their opinions about extending store hours during the holidays. What is the advantage of selecting a stratified random sample, with location as strata, instead of a simple random sample?.

Ateacher attaches a ball to a meter long string and whirls it around in a horizontal circle at constant speed. the teacher explains that the string is what makes the ball go in a circle. why is the string necessary? a) the string is needed to apply a torque to the ball. b) the string is needed to push on the ball to get it up to speed. c) circle motion requires an inertia which is provided by the string. d) circle motion requires a force to give it a centripetal acceleratio