Additional Math Pages & Resources

Wednesday, October 12, 2011

Let's Sort This Out, Part III

This blog is all about using elementary math when you are grown up. This week the subject is sorting data. I have collected, sorted, and studied information about 25 countries from which we have had one or more new visitors.

Here's my data list sorted by Latitude, from lowest to highest. The numbers indicate an angle measured in degrees above or below the equator. The N (or +) in each latitude coordinate means Northern Hemisphere and the S (or -) means Southern Hemisphere.

Sorted by Latitude

In this sort, the lowest numbers are closest to the equator (0 parallel) and the highest numbers are closest to the poles (90). Since the numbers are sorted in ascending order, the lowest ones are at the top, and the numbers get larger (ascend) as you go down the list. Confusing, isn't it?

Perhaps sorting alphabetically is less confusing, because when you do an ascending sort, you start with A at the top and go down to Z.

When you sort data on a spreadsheet, you have to be very aware of the numbers. In order to get the sorting to work properly, I had to add 2 leading zeros 00 in front of single-digit coordinates, and 1 leading zero 0 in front of double-digit coordinates. That way all coordinates had 3 digits and sorted properly.

Now back to the analysis of our countries!

There are a couple countries very close to the equator - Papau New Guinea and the Ivory Coast. The northernmost country is the Faroe Islands, and the southernmost is Botswana. We can deduce that by observing the numbers, and we can see it on the map below, where I have plotted the coordinates. [click the map to enlarge it]

What do we learn? When you sort data, unexpected details emerge! 

Only 6 of the 25 countries are in the Southern Hemisphere.  Why do you suppose there are so few? It appears (after I did some research) that only 10-12% of the population lives in the Southern Hemisphere. As you can see, the Equator line on the map does not go through the middle of my image. If I had evenly presented the map of the earth, you would see lots more water in the Southern Hemisphere.

Most of the world's population live in the Northern Hemisphere. All of Europe, all of North and Central America, all of the Caribbean, the vast majority of Asia and two-thirds of Africa are in the Northern Hemisphere.

No wonder there are more countries in the north ... see what we have learned just by using our elementary math?