Question

make a box-and-whisker plot of the data 21,21,22,20,13,13,27,24

Answer 1

ok, now what?
where do you have trouble? I'm sure your text has examples.
google can provide many more.

Answer 2

Settle down please oobleck. We're just trying to get help. A teacher that teaches in a brick and mortar school can't answer a student's question with "google it." I understand this is different but google doesn't always provide the answer.