Finding the Fourth Proportional to 72,720.69, 109,068.89 and 20,135.49

Step by Step Solution

1. Step 1: Write the proportion equation
   72,720.69 : 109,068.89 = 20,135.49 : x
2. Step 2: Convert to fraction form
   72,720.69/109,068.89 = 20,135.49/x
3. Step 3: Cross multiply
   72,720.69x = 109,068.89 × 20,135.49
4. Step 4: Simplify right side
   72,720.69x = 2,196,155,443.23
5. Step 5: Solve for x
   x = 2,196,155,443.23/72,720.69
6. Step 6: Final answer
   x = 30,199.87