Finding the Fourth Proportional to 139.76, 192.74 and 100.43

Step by Step Solution

1. Step 1: Write the proportion equation
   139.76 : 192.74 = 100.43 : x
2. Step 2: Convert to fraction form
   139.76/192.74 = 100.43/x
3. Step 3: Cross multiply
   139.76x = 192.74 × 100.43
4. Step 4: Simplify right side
   139.76x = 19,355.91
5. Step 5: Solve for x
   x = 19,355.91/139.76
6. Step 6: Final answer
   x = 138.50