Finding the Fourth Proportional to 139,081.71, 191,957.34 and 81,721.02

Step by Step Solution

1. Step 1: Write the proportion equation
   139,081.71 : 191,957.34 = 81,721.02 : x
2. Step 2: Convert to fraction form
   139,081.71/191,957.34 = 81,721.02/x
3. Step 3: Cross multiply
   139,081.71x = 191,957.34 × 81,721.02
4. Step 4: Simplify right side
   139,081.71x = 15,686,949,621.29
5. Step 5: Solve for x
   x = 15,686,949,621.29/139,081.71
6. Step 6: Final answer
   x = 112,789.45