Video Transcript
An actor in a theater wants to
choose random people to go up on stage and participate in the play with him. Which choice is considered a
random sampling method? (A) He chooses those who are
taller than 190 centimeters. (B) He chooses women only. Option (C) he chooses those who
have seats with numbers that were picked from a bowl full of seat numbers. (D) He chooses a third of the
sample to be women and two-thirds to be men. Or option (E) he chooses those
who wear glasses.
Remember, in a random sampling
method, every member of the population has an equal chance of being chosen for
the sample. This instantly rules out option
(A). Anyone shorter than a height of
190 centimeters has a zero percent chance of being chosen. Similarly, if we look at option
(B), we can see that any male would have a zero percent chance of being in the
sample.
So what about our third
option? If we put every seat number in
a bowl and choose one, this should ensure that every seat number has an equal
chance of being chosen. So let’s double-check our final
two options.
In option (D), only a third of
the sample are women, whilst two-thirds are men. Men and women do not have an
equal chance of being chosen. Finally, if we look at option
(E), we see that anyone who doesn’t wear glasses has a zero percent chance of
being chosen.
So the correct answer is option
(C). A random sampling method is
choosing those who have seats with numbers that were picked from a bowl full of
seat numbers.
