Finding the Fourth Proportional to 139,036.60, 208,749.30 and 86,548.60

Step by Step Solution

1. Step 1: Write the proportion equation
   139,036.60 : 208,749.30 = 86,548.60 : x
2. Step 2: Convert to fraction form
   139,036.60/208,749.30 = 86,548.60/x
3. Step 3: Cross multiply
   139,036.60x = 208,749.30 × 86,548.60
4. Step 4: Simplify right side
   139,036.60x = 18,066,959,665.98
5. Step 5: Solve for x
   x = 18,066,959,665.98/139,036.60
6. Step 6: Final answer
   x = 129,943.91