Floating Point - Bit

I am interseted to know how a floating point number is stored in the memory using the 8 bytes it is meant to occupy.

An unsigned 32 bit value for example is stored using four bytes having a range of 0 <= x <= 2^32 -1.

A signed 32 bit value is stored again in four bytes with the last byte used to detemine the sign of the number with a range of -(2^31) <= x <= 2^31 -1.

I have no idea however how a decimal is stored. Does anyone know?

It's more than I want to type..

Here is a tutorial on floating point arithmetic operations --

http://www.cs.utah.edu/~zachary/isp/applets/FP/FP.html