Calculate subsequent proportion:

A recipe calls for 1(1/2) cups of flour to make servings for 6 people.  How much flour should be used to make servings for 4 people?

Solution:

Using x for the flour required for 4 people, the following proportion can be written.

6 people/4 people = 1(1/2) cups/x

The product of the extremes is (6)(x) = 6x.

The product of the means is (4) 1(1/2) = 6

Equate these two products and solve the resulting equation.

6x   = 6

6x/6 = 6/6

X = 1

The unit of x is cups.  Thus, servings for 4 people require 1 cup of flour.