Finding the Fourth Proportional to 72,172.02, 99,598.05 and 39,906.18

Step by Step Solution

1. Step 1: Write the proportion equation
   72,172.02 : 99,598.05 = 39,906.18 : x
2. Step 2: Convert to fraction form
   72,172.02/99,598.05 = 39,906.18/x
3. Step 3: Cross multiply
   72,172.02x = 99,598.05 × 39,906.18
4. Step 4: Simplify right side
   72,172.02x = 3,974,577,710.95
5. Step 5: Solve for x
   x = 3,974,577,710.95/72,172.02
6. Step 6: Final answer
   x = 55,070.89