Finding the Fourth Proportional to 689,796.72, 951,909.72 and 387,990

Step by Step Solution

1. Step 1: Write the proportion equation
   689,796.72 : 951,909.72 = 387,990 : x
2. Step 2: Convert to fraction form
   689,796.72/951,909.72 = 387,990/x
3. Step 3: Cross multiply
   689,796.72x = 951,909.72 × 387,990
4. Step 4: Simplify right side
   689,796.72x = 369,331,452,262.80
5. Step 5: Solve for x
   x = 369,331,452,262.80/689,796.72
6. Step 6: Final answer
   x = 535,420.71