Finding the Fourth Proportional to 72,878.49, 109,317.87 and 20,287.98

Step by Step Solution

1. Step 1: Write the proportion equation
   72,878.49 : 109,317.87 = 20,287.98 : x
2. Step 2: Convert to fraction form
   72,878.49/109,317.87 = 20,287.98/x
3. Step 3: Cross multiply
   72,878.49x = 109,317.87 × 20,287.98
4. Step 4: Simplify right side
   72,878.49x = 2,217,838,760.20
5. Step 5: Solve for x
   x = 2,217,838,760.20/72,878.49
6. Step 6: Final answer
   x = 30,432.01