Draw Inferences From Random Samples Practice Test

A school nurse wants to estimate the average amount of sleep students get per night. She randomly surveys 20 students four different times, getting these average results: 7.2 hours, 6.8 hours, 7.5 hours, and 6.9 hours. A teacher suggests the nurse should survey 100 students just once instead. Which approach is better for making inferences?

A student council wants to predict the winner of a school election between candidates Martinez and Chen. They conduct three random surveys of 40 students each. Survey 1 shows Martinez leading 24-16, Survey 2 shows Chen leading 23-17, and Survey 3 shows Martinez leading 22-18. What conclusion is most appropriate?