Finding the Fourth Proportional to 1,188,404.72, 1,639,991.02 and 644,553.44

Step by Step Solution

1. Step 1: Write the proportion equation
   1,188,404.72 : 1,639,991.02 = 644,553.44 : x
2. Step 2: Convert to fraction form
   1,188,404.72/1,639,991.02 = 644,553.44/x
3. Step 3: Cross multiply
   1,188,404.72x = 1,639,991.02 × 644,553.44
4. Step 4: Simplify right side
   1,188,404.72x = 1,057,061,853,510.11
5. Step 5: Solve for x
   x = 1,057,061,853,510.11/1,188,404.72
6. Step 6: Final answer
   x = 889,479.68