Finding the Fourth Proportional to 100,144.87, 138,215.10 and 57,124.15

Step by Step Solution

1. Step 1: Write the proportion equation
   100,144.87 : 138,215.10 = 57,124.15 : x
2. Step 2: Convert to fraction form
   100,144.87/138,215.10 = 57,124.15/x
3. Step 3: Cross multiply
   100,144.87x = 138,215.10 × 57,124.15
4. Step 4: Simplify right side
   100,144.87x = 7,895,420,104.67
5. Step 5: Solve for x
   x = 7,895,420,104.67/100,144.87
6. Step 6: Final answer
   x = 78,839.99