What is an equation that can be used to solve a proportion?

The Classical Exmple is C = pi d ; The circle circumference and 'd' the diameter. 'pi' is the constant of proportion.

However if given a set of data , that is directly proportional , then we say

y is directly proportional to 'x'

We now equate this by inserting a constant of proportion(k)

Then

Hence

y = kx

Then k = y/x

This is how 'pi' was found.

e.g.

C = 6.2831....

d = 2

Hence

k(pi) = 6.2831... / 2 = 3.141592....

Other sonstants of proportion are

y is inversely proportional to the square of 'x'

Hence

y = k X 1/x^(2)

k = yx^(2)

et.seq.

Hope that helps!!!!