Finding the Fourth Proportional to 139.73, 192.83 and 81.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139.73 : 192.83 = 81.50 : x
2. Step 2: Convert to fraction form
   139.73/192.83 = 81.50/x
3. Step 3: Cross multiply
   139.73x = 192.83 × 81.50
4. Step 4: Simplify right side
   139.73x = 15,714.27
5. Step 5: Solve for x
   x = 15,714.27/139.73
6. Step 6: Final answer
   x = 112.47