Finding the Fourth Proportional to 100,912.50, 139,259.25 and 56,200.50

Step by Step Solution

1. Step 1: Write the proportion equation
   100,912.50 : 139,259.25 = 56,200.50 : x
2. Step 2: Convert to fraction form
   100,912.50/139,259.25 = 56,200.50/x
3. Step 3: Cross multiply
   100,912.50x = 139,259.25 × 56,200.50
4. Step 4: Simplify right side
   100,912.50x = 7,826,439,479.63
5. Step 5: Solve for x
   x = 7,826,439,479.63/100,912.50
6. Step 6: Final answer
   x = 77,556.69