Finding the Fourth Proportional to 71,978.52, 99,328.22 and 40,146.70

Step by Step Solution

1. Step 1: Write the proportion equation
   71,978.52 : 99,328.22 = 40,146.70 : x
2. Step 2: Convert to fraction form
   71,978.52/99,328.22 = 40,146.70/x
3. Step 3: Cross multiply
   71,978.52x = 99,328.22 × 40,146.70
4. Step 4: Simplify right side
   71,978.52x = 3,987,700,249.87
5. Step 5: Solve for x
   x = 3,987,700,249.87/71,978.52
6. Step 6: Final answer
   x = 55,401.25