Finding the Fourth Proportional to 100,816.40, 139,139.88 and 57,812.72

Step by Step Solution

1. Step 1: Write the proportion equation
   100,816.40 : 139,139.88 = 57,812.72 : x
2. Step 2: Convert to fraction form
   100,816.40/139,139.88 = 57,812.72/x
3. Step 3: Cross multiply
   100,816.40x = 139,139.88 × 57,812.72
4. Step 4: Simplify right side
   100,816.40x = 8,044,054,923.27
5. Step 5: Solve for x
   x = 8,044,054,923.27/100,816.40
6. Step 6: Final answer
   x = 79,789.15