Finding the Fourth Proportional to 72,401.32, 108,591.90 and 19,815.40

Step by Step Solution

1. Step 1: Write the proportion equation
   72,401.32 : 108,591.90 = 19,815.40 : x
2. Step 2: Convert to fraction form
   72,401.32/108,591.90 = 19,815.40/x
3. Step 3: Cross multiply
   72,401.32x = 108,591.90 × 19,815.40
4. Step 4: Simplify right side
   72,401.32x = 2,151,791,935.26
5. Step 5: Solve for x
   x = 2,151,791,935.26/72,401.32
6. Step 6: Final answer
   x = 29,720.34