Weight of a rock: in a geology course, students are learning to use a balance scale to accurately weigh rocks. one student plans to weigh a rock 20 times and then calculate the average of the 20 measurements to estimate her rock's true weight. a second student plans to weigh a rock 5 times and calculate the average of the 5 measurements to estimate his rock's true weight. suppose the students construct a 95% confidence interval for the true weight of their rocks. whose interval do you expect to be more precise (narrower)? group of answer choices the student who weighed the rock 20 times. the student who weighed the rock 5 times. both intervals would be equally precise.