Finding the Fourth Proportional to 100,818.72, 139,128.48 and 56,106.72

Step by Step Solution

1. Step 1: Write the proportion equation
   100,818.72 : 139,128.48 = 56,106.72 : x
2. Step 2: Convert to fraction form
   100,818.72/139,128.48 = 56,106.72/x
3. Step 3: Cross multiply
   100,818.72x = 139,128.48 × 56,106.72
4. Step 4: Simplify right side
   100,818.72x = 7,806,042,671.39
5. Step 5: Solve for x
   x = 7,806,042,671.39/100,818.72
6. Step 6: Final answer
   x = 77,426.52