Finding the Fourth Proportional to 139,864.12, 209,794.61 and 83,719.91

Step by Step Solution

1. Step 1: Write the proportion equation
   139,864.12 : 209,794.61 = 83,719.91 : x
2. Step 2: Convert to fraction form
   139,864.12/209,794.61 = 83,719.91/x
3. Step 3: Cross multiply
   139,864.12x = 209,794.61 × 83,719.91
4. Step 4: Simplify right side
   139,864.12x = 17,563,986,601.47
5. Step 5: Solve for x
   x = 17,563,986,601.47/139,864.12
6. Step 6: Final answer
   x = 125,578.93