colorsys: RGB to YIQ transform matrix

[Edward C. Jones]

In colorsys.rgb_to_yiq, the matrix of the linear transformation used is

     .30  .59  .11
     .60 -.28 -.32
     .21 -.52  .31

The places I checked on the Internet use

     .299  .587  .114
     .596 -.275 -.321
     .2.1 -.523  .311

Why does colorsys use a 2 decimal place wersion of the array? What is 
the actual definition of the RGB to YIQ transform?