Finding the Fourth Proportional to 71,748.72, 99,004.32 and 39,915.36

Step by Step Solution

1. Step 1: Write the proportion equation
   71,748.72 : 99,004.32 = 39,915.36 : x
2. Step 2: Convert to fraction form
   71,748.72/99,004.32 = 39,915.36/x
3. Step 3: Cross multiply
   71,748.72x = 99,004.32 × 39,915.36
4. Step 4: Simplify right side
   71,748.72x = 3,951,793,074.36
5. Step 5: Solve for x
   x = 3,951,793,074.36/71,748.72
6. Step 6: Final answer
   x = 55,078.24