Finding the Third Proportional to 316,363.50 and 686,718

Step by Step Solution

1. Step 1: Write the proportion equation
   316,363.50 : 686,718 = 686,718 : x
2. Step 2: Convert to fraction form
   316,363.50/686,718 = 686,718/x
3. Step 3: Cross multiply
   316,363.50x = 686,718 × 686,718
4. Step 4: Simplify right side
   316,363.50x = 471,581,611,524
5. Step 5: Solve for x
   x = 471,581,611,524/316,363.50
6. Step 6: Final answer
   x = 1,490,632.17