Draw the Boxplot

Question

Areas of Islands The data show the sizes in square miles of notable islands in the Baltic Sea and the Aleutian Islands.

Baltic Sea Aleutian Islands
218	343
1154	1042
606	1567
1158	685
2772	272

Draw the boxplot for the given data for the Baltic Sea. Round your answers to the nearest ten.

Answer 1

First, put the data in order from smallest to largest. Then determine what number is in the middle. That is the median. The median breaks the data into two halves. Now determine what number is in the middle of the first half. That will be Q1. Then determine what number is in the middle of the second half. That will be Q3.

In this case, there is no number in the middle so you must take the average of 685 and 1042 to get the median. That will be (685 + 1042)/2 = 863.5 so the median is 863.5. Q1 is 343 and Q3 is 1158.

The box plot will look like a number line with a box above it. The ends of the box will be at 343 and at 1158. You will draw a line at the median which is 863.5. Usually, you draw "whiskers" that extend to the largest and smallest values in the data. Like this:

I didn't round my answers to the nearest 10 - you'll need to do that. I wanted to keep the numbers exact so you could see how to do it.