Since in list values have one decimal place and range from 3.9 to 5.1, I won't use a scale of, say, zero to ten, marked off by ones. Instead, I'll draw a number line from 3.5 to 5.5, and mark off by tenths.
Now I'll mark off the minimum and maximum values, and Q1,Q2, andQ3:
and the "box" part of the plot goes fromQ1toQ3:
And then the "whiskers" are drawn to the endpoints:
Please let me know if you need any clarification. I'm always happy to answer your questions.