Video Transcript
Suppose your school has 500
students and you need to conduct a short survey on the quality of the food
served in the cafeteria. You decide that a sample of 10
students would be sufficient for your purposes. So you choose 10 students by
assigning them each a number and then using the random button on your calculator
to choose 10 students randomly out of the 500 and conduct the survey on
them. Is that considered a simple
random sample?
Remember, a simple random
sample is a nonempty subset of the population where every member has an equal
chance of being in that subset. In this case, we want to choose
10 students from 500. So, at first glance, it does
look like we have a simple random sample. But let’s check that this
selection is indeed random.
In fact, the word “random” is
in the wording of the question. We’re told that each person is
assigned a number, and then the random number button on a calculator is
used. In this method, any two
students will have the same probability of being chosen. So the correct answer is
yes. This is indeed considered a
simple random sample.
