Finding the Fourth Proportional to 72,731.88, 109,085.46 and 20,129.07

Step by Step Solution

1. Step 1: Write the proportion equation
   72,731.88 : 109,085.46 = 20,129.07 : x
2. Step 2: Convert to fraction form
   72,731.88/109,085.46 = 20,129.07/x
3. Step 3: Cross multiply
   72,731.88x = 109,085.46 × 20,129.07
4. Step 4: Simplify right side
   72,731.88x = 2,195,788,860.32
5. Step 5: Solve for x
   x = 2,195,788,860.32/72,731.88
6. Step 6: Final answer
   x = 30,190.18