Finding the Fourth Proportional to 100,917.50, 139,270.47 and 56,205.50

Step by Step Solution

1. Step 1: Write the proportion equation
   100,917.50 : 139,270.47 = 56,205.50 : x
2. Step 2: Convert to fraction form
   100,917.50/139,270.47 = 56,205.50/x
3. Step 3: Cross multiply
   100,917.50x = 139,270.47 × 56,205.50
4. Step 4: Simplify right side
   100,917.50x = 7,827,766,401.59
5. Step 5: Solve for x
   x = 7,827,766,401.59/100,917.50
6. Step 6: Final answer
   x = 77,566.00