Finding the Fourth Proportional to 1,231,990.38, 1,700,128.50 and 688,134.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,231,990.38 : 1,700,128.50 = 688,134.12 : x
2. Step 2: Convert to fraction form
   1,231,990.38/1,700,128.50 = 688,134.12/x
3. Step 3: Cross multiply
   1,231,990.38x = 1,700,128.50 × 688,134.12
4. Step 4: Simplify right side
   1,231,990.38x = 1,169,916,429,234.42
5. Step 5: Solve for x
   x = 1,169,916,429,234.42/1,231,990.38
6. Step 6: Final answer
   x = 949,614.91