Finding the Third Proportional to 315,861 and 690,769.50

Step by Step Solution

1. Step 1: Write the proportion equation
   315,861 : 690,769.50 = 690,769.50 : x
2. Step 2: Convert to fraction form
   315,861/690,769.50 = 690,769.50/x
3. Step 3: Cross multiply
   315,861x = 690,769.50 × 690,769.50
4. Step 4: Simplify right side
   315,861x = 477,162,502,130.25
5. Step 5: Solve for x
   x = 477,162,502,130.25/315,861
6. Step 6: Final answer
   x = 1,510,672.42