Finding the Third Proportional to 315,489 and 684,491.50

Step by Step Solution

1. Step 1: Write the proportion equation
   315,489 : 684,491.50 = 684,491.50 : x
2. Step 2: Convert to fraction form
   315,489/684,491.50 = 684,491.50/x
3. Step 3: Cross multiply
   315,489x = 684,491.50 × 684,491.50
4. Step 4: Simplify right side
   315,489x = 468,528,613,572.25
5. Step 5: Solve for x
   x = 468,528,613,572.25/315,489
6. Step 6: Final answer
   x = 1,485,087.00