Leo wants to determine the average number of texts middle school students send in a day. since all middle school students are enrolled in history, he randomly surveyed 4 students from each of mr. barnes’s eighth-grade history classes. ms. lopez and mrs. frank also teach eighth-grade history. what should leo do to ensure his sample is representative of all middle school students?
a. he should take the sample as is because he randomly surveyed students in each of mr. barnes’s classes.
b. he should also take a sample from ms. lopez’s and mrs. frank’s classes so that each student has the same chance of being chosen.
c. he should survey each of the other history classes. only one grade is being surveyed by this method.
d. he should survey all the students in all the history classes to make sure he collects enough data.