Finding the Fourth Proportional to 72,081.90, 99,471.27 and 39,819.21

Step by Step Solution

1. Step 1: Write the proportion equation
   72,081.90 : 99,471.27 = 39,819.21 : x
2. Step 2: Convert to fraction form
   72,081.90/99,471.27 = 39,819.21/x
3. Step 3: Cross multiply
   72,081.90x = 99,471.27 × 39,819.21
4. Step 4: Simplify right side
   72,081.90x = 3,960,867,389.10
5. Step 5: Solve for x
   x = 3,960,867,389.10/72,081.90
6. Step 6: Final answer
   x = 54,949.54