Finding the Fourth Proportional to 71,940.57, 99,274.33 and 39,680.80

Step by Step Solution

1. Step 1: Write the proportion equation
   71,940.57 : 99,274.33 = 39,680.80 : x
2. Step 2: Convert to fraction form
   71,940.57/99,274.33 = 39,680.80/x
3. Step 3: Cross multiply
   71,940.57x = 99,274.33 × 39,680.80
4. Step 4: Simplify right side
   71,940.57x = 3,939,284,833.86
5. Step 5: Solve for x
   x = 3,939,284,833.86/71,940.57
6. Step 6: Final answer
   x = 54,757.49