Ratio

Ratio

1. A ratio is a quotient of two quantities

   • EXAMPLE: In a supermarket they sell jars of peanut butter with the following prices: 18-oz $1.50 40-oz $4.14 64-oz $6.29 which size is the cheapest?

2. Proportion

   • A proportion is a statement that says that two ratios are equal
   • a, b, c and d are the terms of the proportion. a and d are the extremes. b and c are the means a/b = c/d
   • CROSS PRODUCTS
     • We can found the products of ad and bc by multiplying diagonally
   • DIRECT & INVERSE VARIATION
     • Direct Variation
       • "y" varies directly as "x" or "y" directly proportional to "x", if there exists a nonzero constant "k" it is called CONSTANT OF VARIATION
     • Inverse Variation
       • "y" varies inversely as "x" if there exists a nonzero real number "k" also "y" varies inversely as the nth power of "x" if there exists a nonzero real number
   • EXAMPLES *Solving Proportions *Solving an Equation Using Cross Products *Using a Porportion to Predict Population