Box plot range and IQR
The question
What is the interquartile range?
Scores on the spelling test (points)
How it works.
left whisker end:15 points
left whisker end:15 points
left edge of the box:25 points
left whisker end:15 points
left edge of the box:25 points
line inside the box:30 points
left whisker end:15 points
left edge of the box:25 points
line inside the box:30 points
right edge of the box:40 points
left whisker end:15 points
left edge of the box:25 points
line inside the box:30 points
right edge of the box:40 points
right whisker end:55 points
left whisker end:15 points
left edge of the box:25 points
line inside the box:30 points
right edge of the box:40 points
right whisker end:55 points
left whisker end:15 points
left edge of the box:25 points
line inside the box:30 points
right edge of the box:40 points
right whisker end:55 points
15 points
- 01
A box plot is five numbers drawn to scale. Read the five marks one at a time.
- 02
Left whisker end: 15 points — the smallest value.
- 03
Left edge of the box: 25 points — the quarter mark — a quarter of the data is below it.
- 04
Line inside the box: 30 points — the MEDIAN, not the mean and not the middle of the box's width.
- 05
Right edge of the box: 40 points — the three-quarter mark.
- 06
Right whisker end: 55 points — the largest value.
- 07
Now the question. It asks for the left whisker end, which we just read.
- 08
So the answer is 15 points.