Finding the Fourth Proportional to 71,801.72, 99,081.60 and 39,969.80

Step by Step Solution

1. Step 1: Write the proportion equation
   71,801.72 : 99,081.60 = 39,969.80 : x
2. Step 2: Convert to fraction form
   71,801.72/99,081.60 = 39,969.80/x
3. Step 3: Cross multiply
   71,801.72x = 99,081.60 × 39,969.80
4. Step 4: Simplify right side
   71,801.72x = 3,960,271,735.68
5. Step 5: Solve for x
   x = 3,960,271,735.68/71,801.72
6. Step 6: Final answer
   x = 55,155.67