Finding the Fourth Proportional to 100,824.75, 139,138.16 and 56,123.31

Step by Step Solution

1. Step 1: Write the proportion equation
   100,824.75 : 139,138.16 = 56,123.31 : x
2. Step 2: Convert to fraction form
   100,824.75/139,138.16 = 56,123.31/x
3. Step 3: Cross multiply
   100,824.75x = 139,138.16 × 56,123.31
4. Step 4: Simplify right side
   100,824.75x = 7,808,893,805.89
5. Step 5: Solve for x
   x = 7,808,893,805.89/100,824.75
6. Step 6: Final answer
   x = 77,450.17