Finding the Third Proportional to 456,506 and 686,139

Step by Step Solution

1. Step 1: Write the proportion equation
   456,506 : 686,139 = 686,139 : x
2. Step 2: Convert to fraction form
   456,506/686,139 = 686,139/x
3. Step 3: Cross multiply
   456,506x = 686,139 × 686,139
4. Step 4: Simplify right side
   456,506x = 470,786,727,321
5. Step 5: Solve for x
   x = 470,786,727,321/456,506
6. Step 6: Final answer
   x = 1,031,282.67