Finding the Fourth Proportional to 139.56, 192.56 and 81.34

Step by Step Solution

1. Step 1: Write the proportion equation
   139.56 : 192.56 = 81.34 : x
2. Step 2: Convert to fraction form
   139.56/192.56 = 81.34/x
3. Step 3: Cross multiply
   139.56x = 192.56 × 81.34
4. Step 4: Simplify right side
   139.56x = 15,662.83
5. Step 5: Solve for x
   x = 15,662.83/139.56
6. Step 6: Final answer
   x = 112.23