Finding the Fourth Proportional to 52,087.59, 78,131.52 and 12,644.64

Step by Step Solution

1. Step 1: Write the proportion equation
   52,087.59 : 78,131.52 = 12,644.64 : x
2. Step 2: Convert to fraction form
   52,087.59/78,131.52 = 12,644.64/x
3. Step 3: Cross multiply
   52,087.59x = 78,131.52 × 12,644.64
4. Step 4: Simplify right side
   52,087.59x = 987,944,943.05
5. Step 5: Solve for x
   x = 987,944,943.05/52,087.59
6. Step 6: Final answer
   x = 18,966.99