Finding the Third Proportional to 318,114 and 686,061

Step by Step Solution

1. Step 1: Write the proportion equation
   318,114 : 686,061 = 686,061 : x
2. Step 2: Convert to fraction form
   318,114/686,061 = 686,061/x
3. Step 3: Cross multiply
   318,114x = 686,061 × 686,061
4. Step 4: Simplify right side
   318,114x = 470,679,695,721
5. Step 5: Solve for x
   x = 470,679,695,721/318,114
6. Step 6: Final answer
   x = 1,479,594.41