Finding the Fourth Proportional to 102,131.78, 140,941.50 and 57,419.78

Step by Step Solution

1. Step 1: Write the proportion equation
   102,131.78 : 140,941.50 = 57,419.78 : x
2. Step 2: Convert to fraction form
   102,131.78/140,941.50 = 57,419.78/x
3. Step 3: Cross multiply
   102,131.78x = 140,941.50 × 57,419.78
4. Step 4: Simplify right side
   102,131.78x = 8,092,829,922.87
5. Step 5: Solve for x
   x = 8,092,829,922.87/102,131.78
6. Step 6: Final answer
   x = 79,239.10