the blood bank wants to carry out an investigation to determine the distribution of blood groups of 1200 learners in a high school. Theu decide to use a sample to do their investigation in order ti save costs and time. They also want to get a reliable result. 1)state any 4 planning steps that the blood bank should put in placd to do this investigation before they draw blood from the learners, using a syringe. 2) State 3 precautions tgat the blood bank should take when drawing blood from the learners.​