Finding the Fourth Proportional to 72,405, 99,910.80 and 40,569.30

Step by Step Solution

1. Step 1: Write the proportion equation
   72,405 : 99,910.80 = 40,569.30 : x
2. Step 2: Convert to fraction form
   72,405/99,910.80 = 40,569.30/x
3. Step 3: Cross multiply
   72,405x = 99,910.80 × 40,569.30
4. Step 4: Simplify right side
   72,405x = 4,053,311,218.44
5. Step 5: Solve for x
   x = 4,053,311,218.44/72,405
6. Step 6: Final answer
   x = 55,981.10