Finding the Fourth Proportional to 139,449.78, 208,657.89 and 83,320.43

Step by Step Solution

1. Step 1: Write the proportion equation
   139,449.78 : 208,657.89 = 83,320.43 : x
2. Step 2: Convert to fraction form
   139,449.78/208,657.89 = 83,320.43/x
3. Step 3: Cross multiply
   139,449.78x = 208,657.89 × 83,320.43
4. Step 4: Simplify right side
   139,449.78x = 17,385,465,117.69
5. Step 5: Solve for x
   x = 17,385,465,117.69/139,449.78
6. Step 6: Final answer
   x = 124,671.87