Finding the Fourth Proportional to 71,978.01, 99,329.81 and 40,146.09

Step by Step Solution

1. Step 1: Write the proportion equation
   71,978.01 : 99,329.81 = 40,146.09 : x
2. Step 2: Convert to fraction form
   71,978.01/99,329.81 = 40,146.09/x
3. Step 3: Cross multiply
   71,978.01x = 99,329.81 × 40,146.09
4. Step 4: Simplify right side
   71,978.01x = 3,987,703,291.21
5. Step 5: Solve for x
   x = 3,987,703,291.21/71,978.01
6. Step 6: Final answer
   x = 55,401.69