LEARN MATH STEP BY STEP THROUGH VERY EASY PROCESS

INTRODUCTION OF PROPORTION

__PROPORTION__

**Four
quantities w, x, y, & z are said to be in proportion if w : x = y : z**

** It
also can be expressed as w : x :: y :
z **

** It’s not necessary
for all the four quantities forming a proportion to be of the same kind, the
two quantities forming the first ratio must be of the same kind and so should
be the two quantities forming the second ratio.**

**There are some Types & Rules are discussed below -**

**Cross Product Rules -**

**Suppose, w, x, y, and z are the 1 ^{st}, 2^{nd}, 3^{rd}, and 4^{th} terms of the proportion respectively then
the equation would be w : x = y : z . The 1^{st} & 4^{th} terms are called EXTREMES and 2^{nd} & 3^{rd} terms are called MEANS.**

** The 4 ^{th}
term z is also called the Fourth Proportional to w, x, y**

** 1 ^{st} Term 3^{rd} Term w y**

** So, ----------- = ------------ ; ------- = ------- **

__
__

** 2 ^{nd} Term 4^{th} Term x z**

__CONTINUED
PROPORTION –__

**When three quantities x, y, z are said to be
in Continued Proportion or Continued Ratio then the equation would be
x : y = y : z . **

**The term y is called
the Mean Proportional between x
& z while the term z is called Third
Proportional to x & y.**

** x y**

** In this case , ---------
= --------- , xz = y²**

**
**

** y z**