# Posts Tagged ‘ mathematics ’

## Twitter Math Puzzle and Solution

July 7, 2011
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Yesterday I posted a very simple math puzzle to Twitter that I found in Jonathan Baron’s book, Thinking and Deciding. The puzzle is the following: Show that every number of the form ABC,ABC is divisible by 13. The puzzle comes up in Baron’s book as an example of an “insight problem” in which one goes

## Twitter Math Puzzle and Solution

July 7, 2011
By

Yesterday I posted a very simple math puzzle to Twitter that I found in Jonathan Baron’s book, Thinking and Deciding. The puzzle is the following: Show that every number of the form ABC,ABC is divisible by 13. The puzzle comes up in Baron’s book as an example of an “insight problem” in which one goes

## B*tchin’ six dimensional 6-cube. The rainbow colours and…

July 1, 2011
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B*tchin’ six dimensional 6-cube. The rainbow colours and glass panes really help this visualisation.  Examples of 6-dimensional things If it’s hard to envision 6 dimensions, consider this: the possible tunings of a guitar constitute a 6-dimensio...

## B*tchin’ six dimensional 6-cube. The rainbow colours and…

July 1, 2011
By

B*tchin’ six dimensional 6-cube. The rainbow colours and glass panes really help this visualisation.  Examples of 6-dimensional things If it’s hard to envision 6 dimensions, consider this: the possible tunings of a guitar constitute a 6-dimensio...

## Easiest way to start imagining four-dimensional things is by…

January 15, 2011
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Easiest way to start imagining four-dimensional things is by numbering the corners of a 4-cube. First realize that the eight corners of a cube can be numbered “in binary” 000—001–010–100—110–101–011—111. Just like the four corners of ...

## Easiest way to start imagining four-dimensional things is by…

January 15, 2011
By

Easiest way to start imagining four-dimensional things is by numbering the corners of a 4-cube. First realize that the eight corners of a cube can be numbered “in binary” 000—001–010–100—110–101–011—111. Just like the four corners of ...

## cumsum ( rnorm(50), lend="butt", lwd=12, type="h" ) Cumulative…

December 8, 2010
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cumsum ( rnorm(50), lend="butt", lwd=12, type="h" ) Cumulative sum of 50 draws from a normal distribution. File this under mysteries of the Central Limit Theorem.

## Central Limit Theorem A nice illustration of the Central Limit…

October 20, 2010
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Central Limit Theorem A nice illustration of the Central Limit Theorem by convolution.in R: Heaviside 0,1,0) }HH

## Here is how to improve your charts, graphs, maps, and…

October 2, 2010
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Here is how to improve your charts, graphs, maps, and plots: Erase non-data ink. Erase redundant data ink. Maximize the ratio of data to ink. Show data variation, not design variation. The surface area of graphical elements should be directly proportio...

## extrapolation and interpolation The most important lesson I…

May 25, 2010
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extrapolation and interpolation The most important lesson I learned from this book:  regression is reliable for interpolation, but not for extrapolation.  Even further, your observations really need to cover the whole gamut of causal variables, inter...