Finding the Fourth Proportional to 72,789.20, 109,118.85 and 28,405.63

Step by Step Solution

1. Step 1: Write the proportion equation
   72,789.20 : 109,118.85 = 28,405.63 : x
2. Step 2: Convert to fraction form
   72,789.20/109,118.85 = 28,405.63/x
3. Step 3: Cross multiply
   72,789.20x = 109,118.85 × 28,405.63
4. Step 4: Simplify right side
   72,789.20x = 3,099,589,679.13
5. Step 5: Solve for x
   x = 3,099,589,679.13/72,789.20
6. Step 6: Final answer
   x = 42,583.10