Finding the Fourth Proportional to 72,172.92, 99,594.59 and 39,905.67

Step by Step Solution

1. Step 1: Write the proportion equation
   72,172.92 : 99,594.59 = 39,905.67 : x
2. Step 2: Convert to fraction form
   72,172.92/99,594.59 = 39,905.67/x
3. Step 3: Cross multiply
   72,172.92x = 99,594.59 × 39,905.67
4. Step 4: Simplify right side
   72,172.92x = 3,974,388,144.82
5. Step 5: Solve for x
   x = 3,974,388,144.82/72,172.92
6. Step 6: Final answer
   x = 55,067.58