Archive for the ‘Normal Distribution’ Category


12 minute Maths Guru

July 4, 2011

Meet Salman Khan. He has put free maths on-line.

This article on Salman appeared in The Sunday Times, UK, 12 JUN 2011.

Salman, 28, started putting tutes online for his 12-year-old niece, Nadia, and things grew. So far the Kahn Academy’s claim to fame are:

* Over 2,400 videos including hundreds and hundreds of 12-minute maths tutes

* Over 63,000,000 lessons delivered.

* Bill Gates kids use the site.

* A staff of 1 with funding from The Bill and Melinda Gates Foundation.

* Tutes on Biology, Chemistry and Physics too.

You can look up the maths tutes by topic @ The Khan Academy.

Or search topics on Youtube eg. Introduction to Conics Khan

Why Does Mathspig like The Kahn Academy? Because it’s:

1. Free.

2. Quick

3. Clear

4. Low-key







Salman gives digital chalk-and-talk tutes like a teacher. He hand draws the equations and graphs. He uses a calculator from time to time, but he tends not to use whizz bang spreadsheet graphs or perfectly presented textbook equations. It’s a bit wobbly and it’s all coming from Salman’s head.

And students like this approach. It makes maths look do-able.

Go, Salman.

Mathspig thinks you are just GORGEOUS!!!!!!!!!

 Australia’s Year 7 – 12 Maths Curriculum is already on-line and free, funded by McDonald’s. See What are maths teachers for, sir?

The tutes on Maths Online are produced by Aussie Maths teachers and they are very good. Mathspig, of course, imagined the quadratic function tutes might look something like this:


Mathspig A Go Go!!!!

November 22, 2009

Mathspig is dizzy with excitement over worldwide interest in recent posts. Mathspig keeps in touch with Sarah Ebner (right )who edits the fabulous and informative   Schoolgate Blog, Timesonline (UK). Sarah highlighted my post 10 Biggest Maths Disasters in the World  last week and the response was overwhelming ( for a pig!)

 It is a part of Mathspig’s Mission to get teachers, students, anyone talking about maths. That happened. 

 Meanwhile, one of Mathspig’s favourite maths bloggers is Jeff Trevaskis ( Right. Sorry, Jeff, it’s my favourite pic of you.). Jeff teachers high school maths in country Victoria, Australia, and finds time to run Webmaths, which tackles both fun issues and serious maths. One of his recent entries was titled SMELLY JOCKS?

A recent survey published in the Courier Mail suggested that more than half Aussie men wore the same undies for up to 3 days in a row. Eghhhhhh! I suggested to Jeff that an anonymous survey of, um, male students would probably produce a Normal Distribution or Bell Curve. But we’ll have to dub this one the SMELL CURVE.




But Baby, my Feets too Big!!!!!

September 22, 2009

Confused_tnsThose Hippie Statisticians at The Australian Bureau of Statistics (ABS)  are Navel Gazing Again!!!! . Here are the statistics for the height of students belly buttons above the ground for Year 4 – 12 students. ABS  #mce_temp_url#





height chart Correction


tom & kate


policeman_stop_tns Stop!!! WARNING!!!

Before we do any maths with students height mathspigs, be warned. Students can be teased or embarrassed by their height. Mathspig has always argued that a lampost is tall but does not have much of a personality. And a bee is very small but you’d be crazy to tease one. Nevertheless we will use celebrity heights and average student heights instead. 

Here we go!!!!!




 Look at the data. It is useless. THIS IS THE POINT. You have to make sense of data not just sprout numbers. Foot sizes actually shrink!!!! There is insufficient information. The ABS random sample size used was too small. So baby your feet might be too big… but we can’t tell from this data.









 Q2: Does the ‘average’ Aussie student have divine proportions?Da_Vinci_Vitruve_Luc_Viatour

 The Vitruvian Man is a world-renowned drawing created by Leonardo da Vinci around the year 1487. This sketch supposedly represents the perfect proportions in man. Measure Height and Belly Button Height of Vertruvian man. Divide his Belly Button Height by his full height.

We will call this the DIVINE FRACTION. 

How do Aussie Students compare? You have the data needed to calculate the DIVINE FRACTION for each year level.



Q3: How do the average heights of our  students  compare to students in other countries?

If we could took a very, very large number of student heights they would produce the graph below. It is a NORMAL DISTRIBUTION or A BELL CURVE. The curve below is for young adults in the USA. We do not know the actual number of students for each height.  

ADVANCED MATHSPIGS; You will find more data, a cute bar graph using students  and some interesting bimodal graphs (combining the Bell Curves for Female and Male heights) @#mce_temp_url#

How do Aussies compare? See the graphs below. We do not know how many students are involved. We can only say  our average Year 12 student is taller than the majority of their students!!! Ha! HA! If, that is, the data is reliable and the foot sizes suggest maybe NOT.

basket ball height Correction



height bell curve Correction


 Q 4:  How does the average height of  Aussie students for each Year level compare with celebrities? 

The pics and some stats come from The Sunday Age ( Coming Up Short 13th Sept 2009) . Here are some celebrity heights:

Lou Reed, Rock Star    1.65m

Nicolas Sarkozy  French President  1.65m

Napoleon   1.68 m

Syvester Styllone Actor 1.70 – 1.79m (No one is sure.)

Andrew Bogut, Aussie Basketball Champ (Pictured) now playing for the Milwaukee Bucks 2.13m

Tom Cruise, Actor  1.70 m

Katie Holmes, Actor  1.75 m

Nicole Kidman, Actor  1.79mmrocky

Keith Urban, Singer   1.78 m

Aaron Sanderlands and Peter Street, AFL Players    2.11 m

Gary Ablett jnr, AFL Brownlow Medal Winner 2009  1.80m

Roger Federer, Tennis Star    1.85m

Michael Phelps, Olympic Swimmer   1.95m

Grant Hacket, Olympic Swimmer  1.98 m

Liesel Jones, Swimmer  1.78 m

Tyrone Smith, Rugby Union, 1.78 m

Digby Loane, Rugby Union   1.79 m

Cate Blanchett, Actor  1.74 m

bell curve2 Correction